My Most Effective Strategies After Seven Years of Managing Endo - a podcast by Jessica Duffin

from 2022-01-10T16:54:59

:: ::

Okay so as it’s the start of a new year I thought I’d do a reflective type episode.

I’ve been doing this podcast for a couple of years and many of you have been with me on this journey of transformation with my endometriosis, but I realised I’ve not really done an episode where I’ve shared my biggest needle movers in terms of endo strategies. I recently did a live on my key go-to daily strategies and this is a bit similar, but this is all about the things I am certain have made the biggest changes to my symptoms.

Now, they’re not the only changes – supporting my liver, improving my gut health, adhesion work, physiotherapy and many more strategies have made a big difference too, but if for some crazy reason my life depended on it and I had to give just four strategies that I think made the biggest difference, it would be these.

The reason why I’m sharing this is because I’ve seen many people and clients go down rabbit holes with very niche changes. They start researching alkaline water and focusing on only drinking that, or drinking celery juice every day, or drinking apple cider vinegar every day or doing a fast or a juice cleanse. And sure, I’m not saying there aren’t benefits to some of these more nuanced additions (some of them however do more harm than good!), but if your diet is still full of processed foods or you’re drinking alcohol every day, or you’re not getting enough sleep or you have an underlying condition like SIBO, these smaller changes are only going to do so much. So, I’m trying to save you time by giving you an insight as to what really worked for me.

Now of course, this is my personal experience so you may respond differently, but I will say as an endo health coach, that a healthy anti-inflammatory diet and balanced blood sugar are essential to managing endometriosis. That’s why I talk about them so much and why they are at the core of my work with endometriosis clients. How that fits into each client’s life, if at all, is down to the individual, but all of us can benefit from a healthy diet and balanced blood sugar, even if we don’t have endometriosis!

So again, before we get started, the following is my personal experience, not a protocol for you to follow, but I hope that my experience might inspire you with where to start or how to continue on your own journey of healing your endo symptoms. If you do want a more step-by-step protocol based on the science and research, then I have countless articles, podcasts and then of course my classes, courses and coaching that you can use to create your own plan for beating endo.

So let’s get started…

1. Number 1 is anti-inflammatory nutrition. This was the first thing I tried for endometriosis, way back in the beginning when I was waiting for my second operation, about seven years ago.

At that time, my life was miserable. I lived in fear of my endometriosis flares, and my period was excruciating. I would have pain that would start before I was bleeding, sometimes a full 24 hours beforehand, at a level 10 on the pain scale – and then, I’d start bleeding and it would be even worse. The worst of the pain would be for about 48 hours to maybe three days, and by the third day it would start to clear and would be manageable again and would fade away.

Nothing seemed to help for the pain, I would take way too many painkillers and then spend the next couple of days recovering from the number of painkillers I had taken, feeling sick and experiencing migraines and drowsiness.

Feeling desperate, I went down a rabbit hole learning about nutrition for endo and inflammation, and I had so long to wait until my surgery that I decided to give it a go.

Now, to caveat, how I did this is not how I would recommend my client’s do it having now qualified as an endometriosis health coach. So, please don’t take this initial bit as advice, I’m just sharing what I did for context…

So, unfortunately, I didn’t change my diet very strategically. I didn’t do an elimination diet, where you remove certain common inflammatory foods and allergens and then add them back in one by one to see which ones you respond to. Instead, I just removed a handful and pretty much kept them out for the most part, which is not what I would recommend doing now, unless it was a food that you know, for health reasons it’s generally best to keep to minimal amounts, like alcohol and added sugar. But for the most part, I wouldn’t advise clients to just cut out a bunch of foods and never try them again or to stay strictly away from them forever. I guess the difference with me in this scenario is that I had just done a food intolerance test and it showed I was really intolerant to gluten and diary, and when I removed them I felt so much better, the difference in my IBS symptoms and period was so dramatic, that I think that test had been pretty accurate, though generally they’re quite unreliable (an elimination diet is the most effective way to test if you have a food intolerance).

So anyway, I removed gluten, dairy, added sugar and caffeine specifically – I already wasn’t drinking alcohol and so I continued with that, and I was already vegetarian so I went fully vegan at this point and decided to remove eggs too. Back then I wasn’t a health coach and I was confused about the health verdict of eggs at the time (which has changed over the years), so as I wanted to go vegan anyway, I just removed them too. I don’t think I was eating them much anyway, except in baked goods.

And just a side note, if you’re happy to eat animal protein and it fits with your lifestyle and values (because we’re all different and have to do what’s right for us as individuals!), eggs are nutrient dense, great for hormones and healthy, providing that they’re organic, free-range and from hens fed a diet mostly based on grass and foraging. Lean, unprocessed meat can have a role in a healthy anti-inflammatory diet for endometriosis, providing it is grass-fed, organic and free range or wild, to avoid the added hormones and inflammatory chemicals. That’s a big topic for another discussion, but in short, most anti-inflammatory diets in the research show a greater intake of plant foods over meat. The link between red meat and endo is more complex and requires an entire episode itself, the bottom line is that if you do eat red meat, it’s all about quality and quantity. If you want to learn more, I do cover it in my Nutrition for Endo Masterclasses and in the Live and Thrive with Endo course and this will be covered in another episode later in the year, it’s just a guest episode and we haven’t been able to pin a date down yet.

But back to the main point, I did this elimination diet for one month, and had a pain free period. My first pain free period in years. This was the start of my managing endo naturally and holistically.

I then went onto experiment, unfortunately not very strategically as I already shared, and I would add things in here and there, and make changes, and sometimes I would have good periods and sometimes I would have bad, and because I wasn’t being very strategic, I didn’t always know what the cause was. But what I did know is that if I ate a diet low in inflammatory foods, and for me, what I worked out from my experiments is that my biggest inflammatory triggers were sugar, dairy, gluten, caffeine and alcohol, then I had dramatically better periods. I had some hiccups, as I’ll come to explain later, but this change meant that I got my life back.

Now I didn’t just swap these foods for a bunch of processed replacements like soy meat products and gluten free bread, because let’s not forget, processed foods whether veggie, vegan or meat based, are still processed foods – and we know a diet high in processed food is generally inflammatory. Instead, I ensured my diet was rich in whole plant foods that were full of antioxidants, which fight inflammation.

Since then, I’ve come to learn the science behind anti-inflammatory nutrition and a more sustainable approach to changing our diet as part of my training as an endo health coach.

In short, I focus on what we call ‘crowding out’ the inflammatory or processed foods with more nutrient dense whole foods such as vegetables, fruits, healthy fats including olive oil, avocados, fatty fish if applicable, and nuts and seeds; lean protein like beans and legumes, fish and grass-fed organic meat in moderation, and whole grains, gluten free if necessary. These foods are the key foods that come up time and time again in the research as being the basis of an anti-inflammatory diet, the biggest difference is that some diets include a little meat, some not at all and some quite a bit, like the paleo diet – however, as I said before, the key takeaway is that plants outweigh meat and are the star players of an anti-inflammatory diet.

Now of course, every single body is different, so what is generally anti-inflammatory in the research may not be anti-inflammatory to you, so for example, tomatoes are very anti-inflammatory in general and according to the research, but for me, because I have histamine intolerance, they’re inflammatory. So just keep that in mind, there’s no one size fits all for anti-inflammatory nutrition and it also comes down to your personal lifestyle and values.

Then, if or when my client’s feel ready, we go through a short 4-week elimination phase where we remove a small list of common inflammatory foods or allergens, and then we retest them one by one to see which ones are worsening inflammation and endo symptoms.

These days, I personally adopt the 80/20 rule. For the most part, I eat an anti-inflammatory diet, rich in those food groups I mentioned above. Then, occasionally, usually at the weekends, I allow myself to have some foods that aren’t normally in my personal anti-inflammatory diet, like a takeaway (or take out for my American listeners) or added sugar or caffeine.

Now, this is a very short discussion on anti-inflammatory eating, and more so from my personal perspective, so please don’t base any changes on what I’ve shared here. Instead, do further research and listen to my other episodes on anti-inflammatory nutrition for endo or read my articles, or if you want a step-by-step outline on how to make changes safely and realistically, there’s of course my Nutrition for Endo Masterclasses, my course Live and Thrive with Endo or you can work with me one to one. As always, consult your doctor before making any dietary changes! And if you have a history of an eating disorder or currently have one, please work with a nutritionist or dietician and a mental health practitioner before making changes.

But personally, for me, this was the first change I ever made to manage my endo and it will forever be the biggest game changer. This was the pillar that the following changes were built on.

2. Number 2 was adding in anti-inflammatory supplements, specifically curcumin, ginger and magnesium.

When I first started managing endo with nutrition, I would say that my endo was still unpredictable. I was still learning and as you’ll come to see in strategy 3, I didn’t really understand the science behind what my body was and wasn’t responding to. To have a pain free period I felt like I had to eat “perfect” all the time, and that I could never eat any of the foods that I had cut out in the beginning - as soon as I strayed, I would end up having a really bad period that month. I felt like I was just too sensitive, and I had to work really hard to control it. It was incredible that I could even have a pain free period after years of suffering, but trying to maintain that every month was difficult.

I was then offered a curcumin and ginger supplement to trial, both have been shown in studies to be effective pain relievers, and just as effective as NSAIDS, and curcumin has been shown in rat models to directly target endo and reduce lesion size and growth rate, whilst ginger has been shown time and time again to reduce period pain. I wasn’t offered the supplement to test for endo, but actually for immunity, but that month was December and I had already been more relaxed with my eating so I was worried I would have a flare around my period. But then my period arrived and I felt absolutely fine, I still remember my shock and confusion trying to understand what I had done differently.

For me, this was the start of consistently low pain or pain free periods. Adding supplements on top took the edge off and allowed me to be more flexible with my diet and lifestyle. This is when I really moved into the 80/20 rule I shared earlier, because I had more freedom to.

Since that first encounter, I have experimented with lots of supplements and there are some great, incredibly effective ones out there which I share in episodes 130 and 131. For me, I like curcumin because there’s promising research on its effects on endo, when taken consistently it’s just as effective as ibuprofen so has pain relieving benefits daily, it helps to heal leaky gut which is important for keeping inflammation down, it’s a powerful anti-inflammatory and we know inflammation drives pain and it can also help with brain fog. I haven’t actually taken curcumin for a long time because I’ve had to focus on supplements for SIBO and there’s only so many I can take or afford, but for several years this was my go-to and I believe played a huge role in my healing.

I still take ginger to this day, just before and on my period. I would take it daily but unfortunately it burns my bladder because of my interstitial cystitis. However, I use ginger to prevent and reduce any mild cramping that may come with my period, just so I can be sure I can keep to the pain free or low pain levels that I’m used to.

What I love about ginger as well, is that if I find I have higher pain levels than usual, it really pretty much stops them in their tracks. So, for example, if there’s been a birthday or event near my period and I’ve eaten lot of sugar or something I know flares me that I wouldn’t normally eat, I find the ginger means I don’t suffer severely for it, it gets the pain under control quickly. A handful of times I may add a single paracetamol in there if I find it’s not strong enough, but that’s rare!

If you’re interested in the dosing etc. of ginger, have a listen to my supplements episode, episode 131.

Finally, a later addition was magnesium. Magnesium is not only anti-inflammatory, but reduces muscle cramping, has been shown to reduce period pain and PMS, is essential for healthy hormone balance, energy production and helps to stabilise blood sugar, which you’ll learn about in my next strategy. The difference I experience in my energy, my hormones, my moods, my sleep and my period pain with magnesium is extraordinary. I use both magnesium spray on my body daily and directly on my abdomen during my period, and I use magnesium baths throughout the month.

If I feel any cramping during my period, I spray a couple of times on my pelvis, and the cramps literally melt away in minutes, so in that way, I use it for in the moment pain relief as and when needed. But when I use magnesium spray and baths consistently, the need for spray during my period is greatly reduced, I just find my body’s tolerance and resilience is so much higher, I can be more flexible and have less consequences, and it takes a lot more to cause me pain. That doesn’t mean I can eat junk food and sugar every day as long as I use magnesium, I want to be clear that you can’t out supplement a bad diet and eating healthy isn’t just about endo, but all of the other chronic diseases we are at greater risk of with an unhealthy diet, like heart disease, cancer and diabetes. So yes, I still focus on my 80/20 approach, but it means that I can eat out more and have some treats without such severe reactions as I used to.

You know I am all about foundations, so for me, it’s about laying the foundations of good health and then adding in some extra endo support, because we tend to need a little more than the average person. And I feel like these supplements do that for me. They’re the cherry on the top that have really enhanced my endo management and freed up my life.

3. Number 3 is balancing my blood sugar, which came many years later when I started my training as a health coach.

Something I had noticed was despite my endo pain being better, I was always exhausted. I had severe dips during the day which would leave me slumped in my chair and so tired I literally would hold my eyes open whilst staring at my computer. It’s a wonder that no one on my management team pulled me up on it! I additionally had severe brain fog and low moods.

I also felt hungry quickly after big meals, would have trouble sleeping, would wake up tired and starving, and would often feel faint, dizzy, shaky and irritable.

I put this all down to having endometriosis and the chronic fatigue and brain fog that can come with it. I now don’t think it’s as simple as endo causes brain fog and fatigue, I actually think -well, know - there are multiple factors that contribute to these symptoms, and I explore them in episode 119 for those of you who would like to learn more.

I was really interested in understanding why I had managed to clear my endo pain, but not my fatigue and brain fog.

The other issue was that I had noticed that I couldn’t eat heavy carbs on my period without causing a pain flare. I could be pain free, had a great month, but if I ate some fruit, a bowl or oats, rice, grains, pasta or potato, I would be in agony within 30 minutes or so. I started noticing that I was better off sticking to fasting on Day 1 of my period, or eating a small amount of protein, fats and low starchy vegetables for the first 24 hours to two days.

I was also depressed, anxious and had awful PMS and mood swings and spent a good portion of each month feeling suicidal. I do have my suspicions about whether I suffered with PMDD and that it’s now largely under control, but I wasn’t tracking my period and I didn’t even know when my period would start, so I can’t really say whether these feelings were cyclical, but I feel like they were. Regardless, all of that has gone away since balancing my hormones and learning about blood sugar.

And when I finally did learn about blood sugar, it all made sense!

So, let’s do a recap of what blood sugar is and means for the body. Blood sugar is the measurement of glucose a.ka. sugar, in the blood stream. We get glucose from carbohydrates, after they break down in the gut through digestion. Glucose is the body’s main source of fuel, but it needs to be in the right amount to benefit us. Too much and we’ll have problems, too little and we’ll have problems too.

Complex carbohydrates like vegetables, contain fibre and are broken down over time, so you get a steady drip of glucose to the blood stream over a sustained period, which creates even energy levels.

However, simple carbohydrates like processed carbs such as white bread, white pasta and simple sugars like honey, maple syrup and white sugar, contain very little fibre and are made up of only very short chains of glucose. It doesn’t take the body much time at all to break down those chains into single glucose molecules that get absorbed into the blood stream. So, this creates a large spike in blood sugar, in a very short amount of time.

Our body actually finds this spike a stressor, as we’re not designed to have that much glucose in our blood at one time. The body wants to clean up all this glucose quickly, so it releases lots of insulin from our pancreas. Insulin is a hormone that delivers glucose to cells for fuel, but when we have too much glucose, it quickly shoves it away in storage in our fat cells and liver. Because the body has released so much insulin in a panic to sort our blood sugar levels out, our glucose levels end up dropping dramatically and our levels get too low. As a result, our brain and body are now starved of glucose, because all of it has been put into storage and none has been left for actual fuel.

It’s this dip that I was experiencing during my sleep, when I was waking in the morning, when I felt exhausted mid-morning and afternoon, it’s why I would eat a huge meal and feel starving shortly after. It’s why I felt dizzy, shaky, depressed, anxious. It’s also why my moods fluctuated and it’s also why I had severe PMS and oestrogen dominance symptoms, because blood sugar dysregulation drives up oestrogen levels and can lower progesterone levels, creating hormonal imbalances.

Now the other issue is that high blood sugar levels raise inflammatory chemicals called prostaglandins, and we know that inflammation is a driver of pain in endometriosis. This would explain why I would have surges in pain when eating a carb heavy meal during my period, especially when I hadn’t created these meals to be blood sugar balancing. I can now eat a blood sugar balanced meal on my period and not experience any pain at all, which to me is still revolutionary.

At the time, when I was experiencing all of these problems, I was eating a wonderful anti-inflammatory diet rich in an antioxidant rich foods, but I was mainly eating carbs, and wasn’t paying enough attention to protein or healthy fats. I would pile my plate with hummus, potatoes, rice, falafel and vegetables. These aren’t unhealthy foods. Carbs are not the enemy here – as I’ve already explained, the glucose from carbs is essential fuel for us. But it’s about how we eat carbs.

There are a few steps to balancing your blood sugar and I dive into those in more details in other episodes, articles, my course Live and Thrive with Endo and my nutrition masterclasses, but in short, the first step is having a balanced plate. That means having fat, fibre, protein and complex carbs with every meal.

Fat, fibre and protein are not only nutrient dense and provide essential nutrients for managing endo and balancing hormones, but they slow down the release of glucose from carbohydrates because they take longer to digest.

At the IWHI where I trained, we’re taught to balance a plate with 50% of the plate being low starch vegetables like cruciferous veg, peppers, cucumbers, etc., 25% of your plate is protein, whether that’s animal or plant based, and the final 25% is split between healthy fats and extra carbs, usually starchier ones or more veggies, depending on what your body needs. So, for example, it might look like having some root vegetables which are starchier and higher in carbs, or whole grains which again are starchier and higher in carbs, and tend to break down more quickly than low starch veg. For fat, we’re looking at about two tablespoons or two golf ball sized portions.

Now this will need tweaking for each individual, as someone who is very active will probably need more starchy carbs than someone who has a desk job, but regardless, it’s about focusing on those four pillars and their rough portion sizes, adjusting to what feels right to you.

Once I made this change, I felt such a huge difference, I almost think about my health in the sense of before and after blood sugar balancing! My moods are much more stable, my energy is consistent in the sense that I don’t often have those swings anymore or those crashes unless my blood sugar is unstable for some reason, I rarely ever have oestrogen dominance symptoms unless I haven’t taken care of my blood sugar, I don’t have PMS again unless I haven’t taken care of my blood sugar, my brain fog is minimal and I’m much more focused, and I don’t have these surges of pain when I eat on my period anymore.

Of course, if you have an eating disorder or a history of an eating disorder and this feels triggering for you, I don’t recommend you make any changes without the support of a dietician or nutritionist versed in eating disorders and a mental health practitioner.

If you’d like to learn more about blood sugar in-depth, I listed earlier the resources where I provide more step-by-step actions.

4. My last biggest needle mover has been surprising for me and that’s clearing my SIBO, despite having relapsed shortly afterwards.

I haven’t spoken about this much because I wanted to be sure, but even though I am quite certain I have relapsed with my SIBO, since I got a negative test result, I’ve experienced yet again, a new level of resilience in my period, similar to how I felt with adding in those supplements.

Just after I got the all clear we spent six weeks in Greece, where my options for endo friendly foods were limited. I ended up incredibly sick with gut health issues, because I am intolerant to gluten and dairy and having to eat those a few times a week ended up causing a lot of IBS issues, but in the past I would have been in cripplingly agony on my period if I was eating these foods regularly, but instead, whilst I did have an increase in pain, it wasn’t anywhere near how it was previously.

I will say, during treatment my period was up and down because there was a lot of inflammation going on in my body, so it was more coming out on the other side that I’ve seen the difference.

And since treating, I’ve introduced gluten for a coeliac disease test, but again, despite it being worse than normal and I’ve needed to take some time out of work for it, the pain with my periods wasn’t anywhere to the level it would have been in the past.

Secondly, my blood sugar levels have dramatically improved. Prior to treating my SIBO, I would have to work very hard to control my blood sugar levels and I was incredibly sensitive to any increases or dips, now they are much less sensitive and more stable. And even though I could eat more on my period learning how to balance my blood sugar, I still had to eat a low level of carbohydrates to prevent a blood sugar spike, which would normally lead to a pain flare. So, in terms of what I could eat on my period, I had gone from pretty much needing to fast or eating minimal amounts of fat and protein, to then being able to eat low carb meals once I learnt how to balance my blood sugar. However, now the difference is remarkable.

My period was on New Year’s Eve and I truly cannot believe what I ate. I had already noticed over the past months that I was becoming more and more resilient with what I could eat, so we decided to have noodles on New Year’s Eve. Usually, I would stay away from anything with a high carb content on my period because it would just shoot my pain up, but because I had been dipping my toes in over the past few months and as it was New Year’s Eve, I decided to try something I would never normally even consider eating on my period. I’m pretty sure I also ate some of my gluten free bread that day too and probably some other Christmassy carbs. And whilst I got slightly more pain than my usual low pain or pain free periods, with some extra ginger and magnesium, it went away quickly (as in, within half an hour).

So again, just to be clear, I’m not about to fill my diet with foods I know make me sick, like dairy, gluten, caffeine and sugar, and I’m certainly not going to start swapping my veggies for more processed food. But it’s nice to know I don’t have to panic if I eat a slice of birthday cake near my period or if I want a bowl of pasta on my period.

Now you’re probably wondering why treating the SIBO would make a difference. Without offering my body up for research, I can only hypothesize as to what’s happened, but I think I can reasonably believe this is correct.

Firstly, SIBO, especially methane type SIBO, can cause blood sugar imbalances, as can other forms of bacterial imbalances in the gut. I believe that whatever bacteria I specifically had that was behind my SIBO, was driving some of my blood sugar issues. You’ve heard me talk about this for a long time, that even when I ate for blood sugar, I would still notice how sensitive I was to blood sugar changes or a meal that wasn’t perfectly balanced. Now there are numerous bacteria responsible for SIBO, so for example, two people could have methane type SIBO, but the bacteria causing their methane SIBO could be different. I think that the bacteria causing my blood sugar issues has either been cleared entirely and it’s a different bacteria that’s causing my current relapse, or it’s returned but is in low levels so I’m not so affected by it.

Secondly, bacteria from SIBO can release a toxin called endotoxins or lipopolysaccharides. These cause a huge inflammatory reaction in the body and have been found in the pelvic cavity of people with endo and have been shown to contribute to the inflammation and growth of endometriosis. Having cleared SIBO, it’s possible that I may have reduced the level of endotoxins in my blood and pelvic cavity, reducing the inflammation in that area. And as a result, my body is more resilient to changes that can increase inflammation because it’s not already being inflamed by SIBO.

Clearly, I need to get back on top of my SIBO to keep reaping the benefits because I don’t want the endo toxins or bacteria to build up to high levels again. It’s not something I’m doing just yet because I’m working on my root causes, to prevent relapsing again, and as you know, I’ve been exploring candida overgrowth and mould too, which can cause relapse, but all of these things take time. If I notice any negative changes, I’ll try to do the treatment quicker, but for now, I’m enjoying the benefits!

So that’s it. Those are my top four changes that I feel made the biggest difference to my endo symptoms in the past seven years. I hope you’ve found this episode inspiring, motivating and hopeful!

See you next week.

Let's get social! Come say hello on Instagram or sign up to my newsletter.

My new Nutrition for Endo Masterclasses are out now and are on special offer for Black Friday. Get one masterclass for £29.99 (full price £40) or both for £50. Find out more here.

My cookbook This EndoLife, It Starts with Breakfast is out now! Get 28 anti-inflammatory, hormone friendly recipes for living and thriving with endometriosis. Order your copy here.

If you feel like you need more support with managing endometriosis, you can join Your EndoLife Coaching Programme. A 1-to-1 three month health and life coaching programme to help you thrive with endometriosis. To find out more about the programme and to discuss whether it could be right for you, email me at hello@thisendolife.com or visit my website.

This episode is sponsored by The Pod Farm. Learn all about how to start your own podcast with the complete course from The Pod Farm. Aimed at beginners, this course takes a simple and straightforward approach to planning, equipment buying, setting up, recording, editing and hosting your own podcast. With hours of audio and video materials, and downloadable guides and useful links, this multimedia approach aims to have something for every kind of learner. From now until April 15, newsletter subscribers get 20% off the course price. Visit www.thepodfarm.com to enroll or find out more

This episode is sponsored by BeYou. Soothe period cramps the natural way with these 100% natural and discreet menthol and eucalyptus oil stick on patches and CBD range. Click here to find out more and to shop: https://beyouonline.co.uk

This episode is sponsored by Semaine. Try their supplement for period pain and daily supplement for hormonal balance and PMS prevention with code ENDOLIFE to get 20% off your first order.

Show Notes

Anti-inflammatory nutrition

https://www.integrativepainscienceinstitute.com/diet-works-best-pain/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4684110/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4359818/

https://pubmed.ncbi.nlm.nih.gov/11093597/

https://gut.bmj.com/content/65/11/1812.long

https://gut.bmj.com/content/70/7/1287#article-bottom

https://pubmed.ncbi.nlm.nih.gov/23419794/

https://academic.oup.com/endo/article/149/3/1190/2455150

https://pubmed.ncbi.nlm.nih.gov/15051604/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2693127/