Neuroendocrine Cancer Nutrition Series Article 3 – Gut Health


Nutritional issues are one of the biggest challenges affecting most Neuroendocrine Cancer patients.  It is also a key factor in maintaining a decent quality of life and for most countries without adequate NET Specialist Dietitian support, it remains an unmet need. In this article, I’m discussing the use of probiotics to combat the potential issue of small intestine bacterial overgrowth (SIBO) in Neuroendocrine Tumours. 

When I first indicated this nutrition series was under construction, a few people got quite excited anticipating me to produce advice on what to eat.  However, that was never my intention. What people should or should not eat is such a varied problem (or solution?) that anything I said would only really be of help to those for whom it worked – ergo this area is not an exact science and never will be.  I’ve seen several ‘what to or not to eat’ publications/articles out there aimed at NET patients; some more up to date than others – all I would say is to interpret them very very carefully.

What my nutrition series actually covers is what causes the nutritional related issues and to a certain extent, try to work out how to tell if these issues are caused by either treatment or an associated syndrome, leaving fellow patients to make up their own minds about what to eat; or arm themselves with the necessary knowledge whether this applies to them or not.

The first two articles in the series were Article 1 – Vitamin and Mineral Challenges and Article 2 – Malabsorption. These remain popular and have a constant stream of views – no surprise as these are well-known side effects of several types of NETs…… or at least they should be well known.

This particular article “Gut Health” is not as ‘clear cut’ or simple as the first two and I suggest you read Articles 1 and 2 first if you are not familiar with the issues.  Again, I’m grateful to Tara Whyand (NET Specialist Dietician and researcher) for some of the input below.

What is the “Gut” ?

When I first met my surgeon, I found one of his favourite words was ‘Gut‘.  Like me before diagnosis, many of you will have heard or used the word but in an intentionally non-medical context, e.g. guts (bravery), ‘gut feeling’ or ‘gut instinct’ (intuition). I’ll return to that theme later but when you look at these contextual uses of the word, it’s no surprise why some scientists refer to our gut as a ‘second brain’ given the interaction between hormones in the gut and the brain.

I always thought the gut referred to just the ‘belly’ area but in medical parlance, the gut has much bigger geography.  It is sometimes used interchangeably with the term Gastrointestinal (GI) Tract and stretches from the throat to the anus and is responsible (in the most general terms) for food intake, digestion/absorption, waste processing and finally waste ejection. I often refer to it as my ‘plumbing’. NET patients might be familiar with the terms ‘foregut’, ‘midgut’ and ‘hindgut’ which are sometimes used to define the embryological origin and grouping of Neuroendocrine primary tumours, although the boundaries and constituent parts can vary from site to site.  The inclusion of certain anatomical locations as a sub-section of the gut is clearly for convenience rather than anatomical accuracy (e.g. Lung).

This is a massive subject, but I wanted to ‘cut to the chase’ in this article and focus on the use of probiotics to combat the potential issue of small intestine bacterial overgrowth (SIBO) in Neuroendocrine Tumours.  The symptoms and signs of SIBO can be similar to the symptoms and side effects of treatment that many patients report anecdotally on patient forums.  I also found the science is complex and not really 100% tied down.


One of the terms you find in this complex area is the ‘human gut microbiota‘, sometimes known as ‘gut flora‘. Our ‘gut’ harbours a complex community of over 100 trillion microbial cells, approx 3% of our body mass! The human gut microbiota is known to have an influence on every part of our body (including the brain…..) and disruption of this ‘community’ has been linked with several gastrointestinal conditions such as Inflammatory Bowel Disease (IBD) and obesity.

Probiotics are said to help keep the balance and mix of bacteria stable within the gut which can be affected by many different factors, including the use of antibiotics, aging, illnesses (such as IBD), following infective gastroenteritis and (of interest to NET patients) after cancer treatment or gastrointestinal surgery. {1}  Incidentally, the reference here is authored by Tara Whyand and Professor Martyn Caplin (a Neuroendocrine Tumour expert who also happens to be a Gastroenterologist). Useful reading if you have any of the conditions in the report or have had gut surgery (or like me, you are a total geek!).  They are also frequently used in Irritable Bowel Syndrome (IBS).

Small Intestine Bacterial Overgrowth (SIBO)

Another interesting area of research into something called Small Intestinal Bacterial Overgrowth (SIBO), a condition where the small intestine is populated by an abnormal amount and/or types of bad bacteria. It follows that probiotics (good bacteria) may be useful in combatting this by helping to maintain balance.

So how does SIBO potentially and specifically affect NET patients?

  • It can be caused or exacerbated by abdominal surgery to stomach, duodenum, pancreas or via Whipple, small & large intestine,
  • poorly controlled diabetes,
  • the long-term use of Proton Pump Inhibitors (PPI) (e.g. omeprazole and lansoprazole, etc). Several studies link to these drugs including this one,
  • possibly long-term use of antibiotics that can kill good bacteria. Some evidence of surgical involvement can be found here – this link – particularly the bit about the prevalence of patients who have had an “abdominal surgery” or an “Ileocaecal valve resection”.  I guess that would include many NET patients?  (this is a big article so just focus on table 1 near the beginning).

Symptoms vary for everyone from watery diarrhea suddenly starting 20 times a day to just bloating and wind in both directions, to nothing at all.  These symptoms are regularly reported by patients so working out the root cause might need some professional help.

Is there any testing for SIBO?

There is a test to check for SIBO called the Hydrogen breath test. This test uses lactulose ingestion to measure the hydrogen in the breath. If SIBO is diagnosed, treatment is normally via antibiotics. However, advice is to leave a 2-hour gap between taking probiotics and antibiotics and a high dose multi-strain probiotic should be applied.  Our friend Tara has done some work on this alongside Professor Martyn Caplin who was featured at ENETS 2017.

ENETS Research – Assessment of Small Intestinal Bacterial Overgrowth (SIBO) in NET Patients Abstract #1698

Introduction: SIBO is not uncommon in NETs. Hydrogen Breath testing (HBT) using glucose may be more sensitive to proximal SIBO as glucose rarely reaches the colon. Many NET patients are likely to have distal SIBO however, as factors such as ileocecal valve removal apparently increase distal SIBO risk. Thus glucose BT alone may limit sensitivity for detecting SIBO in some NET diagnoses.

Aim(s): Assess likely risk factors for SIBO. Assess sensitivity of additional lactulose HBT and CH4 BT.

Materials and methods: Retrospective data (n=55) of NET patients undergoing HBT was examined. Twelve patients (12/55) who tested negative for glucose HBT but continued to have diarrhoea +/- wind had repeat BT using lactulose. These patients had both H2 & CH4 BT.

Midgut NET diagnoses were most frequently referred for BT (n=43, 78%). Twenty four (24/55, 44 %) had prior right hemicolectomy. Ten (10/24 ,42%) of those were SIBO positive. Ten patients were positive for HBT prior to being given the glucose substrate, they all had abdominal surgery in the past. Twelve patients who tested negative for glucose HBT had repeat testing using lactulose and measured both H2 and CH4 production. This led to an additional 3 (25%) positive results.

Abdominal surgery, especially right hemicolectomy increases the likelihood of a positive glucose HBT. Glucose may still be sensitive in those with risk factors for distal SIBO. Additional lactulose use with H2 and CH4 measurement increases the sensitivity in diagnosing SIBO.

14th Annual ENETS conference (2017)
Presenting Author: Tara Whyand

Keywords: nets, sibo, dysbiosis


One of the first pieces of advice I was given after my initial surgery was to take probiotics – to keep up my stocks of ‘good’ bacteria.  I didn’t really understand why, I just complied. I started with the liquid drinks you can buy in most supermarkets and supplemented this by eating bio-active yogurt.  I didn’t really notice any difference from either except the yogurt was much nicer to eat!

Tara Whyand then confirmed this advice when I first met her in 2012 at a NET Patient conference.  In 2013 when I started looking for a new normal, I realised that the supermarket drinks and yogurts were simply not enough good bacteria for my ‘new plumbing’ and decided to take a high-grade daily capsule containing 5 billion friendly bacteria multiple strains (Tara does recommend at least 2 billion and multiple strain).  Within weeks I was noticing a difference in bowel motility although I confess to changing other elements of my lifestyle at the same time given that I was embarking on finding my new normal – not the best ‘fault finding’ approach!  Nonetheless, I sense probiotics are helping and I won’t be stopping them any time soon.  If you look at several NET-specific dietitian/nutrition presentations, most appear to promote the use of probiotics for NET patients.

My own Experience

I had been taking a 5 billion dosage (containing 3 strains) since 2013 and I stuck with the brand I use for my vitamin and mineral supplements for convenience (and their accreditation as a supplier – see below).  I did increase that to 20 billion once, but it coincided with a bout of constipation. I went back to 5 billion just in case.

I don’t believe the brand is as important as obtaining them from a reputable provider (I accept this can also be a brand). How does one know it’s a reputable provider? For example, in UK, from an MHRA-approved supplier. In the USA, there are standards set by the Pharmaceutical Inspection Convention (PIC) and audited by the TGA – an international government agency that ensures compliance with the FDAs Current Good Manufacturing Practices (cGMP). The UK MHRA accreditation incorporates the cGMP standard. Always check the small print on probiotics. Look for a guarantee of potency – this is the number of Colony Forming Units (CFU) that are active when they reach you. Each strain listed must have an accurate CFU count of each species/strain listed on the label and a guarantee of the CFU count that you can expect at the end of shelf life. Companies that do not state potency at the end of shelf life should be suspicious of quality control. For extra confidence, look for evidence that the potency has been independently verified by a third party such as TGA, or another member of the Pharmaceutical Inspection Convention (PIC) or as above, cGMP compliance.

Multiple strain products are becoming popular. However, there continues to be disagreement in the probiotics industry in regard number of strains vs potency. Lactobacillus and Bifidobacterium appear to be the most important thus why each product has those. Some authors suggest they won’t all make it past the stomach, and some suggest more strains you use can result in completion between the strains for survival. Some claim diversity of strains is important. And as you can see above, some become less potent over time, particularly near the end of their shelf life. Always get advice if you have access to it or do your own homework.

In April 2020.  I started testing a new brand containing 14 strains to see if I can discern any difference.  This type has lower potency but I can always take more.  It was more expensive, but I seem to be coping OK so far.

Having tried the 14-strain product, I could not discern any difference other than cost, so I will return to my 5 billion product in June 2022.

This article could have been 10 x longer!  I didn’t even get to the bit about the relationship between the gut and the brain – perhaps another day?

Other reading (note – none of this should be considered medical advice). 

Article 1 – Vitamin and Mineral Challenges.   This was co-authored by Tara Whyand, UK’s most experienced NET Specialist Dietician.  This blog provides a list of vitamins and minerals that NET Cancer patients are at risk for deficiencies, together with some of the symptoms which might be displayed in a deficiency scenario.

Article 2 – Malabsorption.  Overlapping slightly into Part 1, this covers the main side effects of certain NET surgical procedures and other mainstream treatments. Input from Tara Whyand.

Article 3 – ‘Gut Health’.  This followed on from the first two blogs looking specifically at the issues caused by small intestine bacterial overgrowth (SIBO) as a consequence of cancer treatment. Also discusses probiotics.  Input from Tara Whyand.

Article 4 – Food for Thought.  This is a blog about why certain types of foods or particular foodstuffs can cause issues.

Article 5 – ‘Pancreatic Enzyme Replacement Therapy’. The role of PERT (Creon etc) in helping NET Patients. Input from Tara Whyand.

Article 6 – ‘Tara Whyand Video Series’. A number of fantastic short video coverng a wide range of diet and nutrition issues experienced by NET patients.  

Read a Gut Surgery Diet Booklet authored by Tara – CLICK HERE

You may also appreciate these articles where there is overlap:

The Diarrhea Jigsaw – different things can cause diarrhea, it’s not all about syndromes.

The Constipated NET Patient – yes they exist!

Very grateful to Tara for the input.

Click picture to read more


I am not a doctor or any form of medical professional, practitioner or counsellor. None of the information on my website, or linked to my website(s), or conveyed by me on any social media or presentation, should be interpreted as medical advice given or advised by me.  Neither should any post or comment made by a follower or member of my private group be assumed to be medical advice, even if that person is a healthcare professional as they are not members of the private group or followers of my sites in any official capacity.  Please also note that mention of a clinical service, trial/study or therapy does not constitute an endorsement of that service, trial/study or therapy by Ronny Allan, the information is provided for education and awareness purposes and/or related to Ronny Allan’s own patient experience. This element of the disclaimer includes any complementary medicine, non-prescription over the counter drugs and supplements such as vitamins and minerals.

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22 thoughts on “Neuroendocrine Cancer Nutrition Series Article 3 – Gut Health

  • Martin

    Hi Ronnie long before my stomach tumour metastatic in liver l had two rather major gastric surgerys and for a long number of years been on high doses of lansaprozale and the likes Is the general opinion that this type of drug is not so good having Neuroendicrime tumours Thanks Ronny

  • Deanna Vickery, Mrs

    Hi Ronnie only just read this blog re probiotics; I have been eating onken natural pre-set every day for some years – I can eat very little without bloating and ‘D’ I also take supplements, some of which are from healthspan. Please tell me which strength of probiotic capsule you take from this company. At the end of my tether now…..

    • Hi Deaanna – I take a 5 billion dose. It took me some weeks to notice a difference. This will not work for everyone but it an easy and reasonably cheap way to testing to see if it does! Good luck

      • Bryan Beecher

        How Rony a very interesting read. I had a right hemicolectomy and being diabetic I was prescribed Diasip it is made by Nutria as well as cod liver oil high potency garlic and tumeric and vitimin c mega. I was just holding my own and not able to do a lot if general work around the house. I am 70 years old. About 6 months ago I heard about kombutcha, so I got a Scobey and adequate our own brew we make 7 liters a week ( for 2 of us).
        I started to feel a lot better I live in New Zealand and I heard of a Russian man who had ( smuggled) some kefit grains from kargerstan. I managed to find him and he gave me a teaspoon of grains which would produce about 50 ml of kefir a day I concentrated on increasing the grains which I managed by using organic whole milk. Now I have over 100 grams of grain and make about 2 litres of kefir a week.
        I feel really well and my energy levels and bowel problems have gone. As a side effect six months ago my hair and beard was snow white ( my wife was the same) Both our hair colour is getting darker by the week. My liver results have all returned to normal levels and I feel like a million dollars.
        When I add kefir to my Diasip it instantly turns it into a thick creamy drink. Unfortunately my gat8 scan showing uptake in Mt prostate and my psa has gone up my doc is keeping a close eye on me and doing 3 monthly psa checks I also have a lot of lymph node which have stopped growing so that’s a bonus
        Kind regards
        Bryan Beecher

  • Cherie Thamm.

    Sorry, senior moment. I did read it but that had slipped through. 😊. I’m getting information overload!

      • Cherie Thamm.

        :). I take it you don’t have any info on the types of probiotics available? Refrigerated capsules versus shelf-stored ones? I can’t afford to shell out for the expensive fridge ones especially if the others are as good.

      • I think I replied to that further down 🙂 Here it is again “Thanks for the comment Cherie. With the probiotic drinks and yoghurts, you would naturally store in a fridge and that is the storage instructions on their labels. However, with capsules, they need only be stored in a dry cool place. They are definitely recommended for overseas trips where you may be more at risk from picking up bad bacteria etc. Bacterial overgrowth can make wind worse so yes 😁 ”

        I use a capsules from a company called Healthspan

  • I’ll be having the hydrogen breath test in September and I have learnt something about the reasons for this test – thank you.
    I’m concerned that treatment is by antibiotics. There is a lot of noise these days about bacteria becoming resistant to antibiotics.

    • Yes there’s always chatter about antibiotics. However for some things there is no other treatment. There is also some advice about separating out antibiotics and probiotics by a few hours which is important in a similar context. I’d love to hear how you get on with the test?

  • Vickie Shackett

    My Gastro Doc has me on my own choice of probiotic which I have chosen and it contains 10 billion cfu and also I have a prescription for the treatment of SIBO. I learned all about this a few years ago when I had abdominal pain, constipation, slow moving bowels due to the Sandostatin LAR. I have and am being treated for SIBO as he firmly believes with the loss of bowel due to resections and the medications I am on that this is indeed my situation – SIBO. I am glad my Gastro Doc was able to help me with this and the medication has been definitely great! Glad to see you have written about this subject.

    • Thanks Vickie, I only found out about this recently but at least I’ve been taking probiotics for much longer. Looking at the most common issues on forums, I would think many people might be suffering with SIBO and don’t know. I’m going to ask for a test.

  • Cherie Thamm.

    I’ve heard that there’s no benefit in taking any probiotics that aren’t kept in the fridge. Is that correct? I’m taking my hubby, who has NETs, to China in October and was wondering if I should get him some probiotics to help with the “wind” situation. Don’t want him embarrassing himself! I live in Australia and find your blog very helpful. Thank you.

    • Thanks for the comment Cherie. With the probiotic drinks and yoghurts, you would naturally store in a fridge and that is the storage instructions on their labels. However, with capsules, they need only be stored in a dry cool place. They are definitely recommended for overseas trips where you may be more at risk from picking up bad bacteria etc. Bacterial overgrowth can make wind worse so yes 😁

      • Cherie Thamm.

        Thanks, Ronny. In Aus we have a brand called “Ethical Nutrients” that advertise heavily and their product is kept in the fridge. It’s only been in the last couple of years that I’ve noticed other non fridge ones being advertised and I think these are the ones that are being referred to as “iffy” . The fridge ones are a whole lot more expensive than the others. Just wondering if there is a huge difference.

  • Especially like the bit about the probiotics, I have taken these for a while due to having had to take a lot of antibiotics over a long period of time, and I have now also started to make my own yogurt as an extra boost😃

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