Neuroendocrine Cancer Nutrition Series – Article 3 – Gut Health

OPINION.  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 – this area is not an exact science. 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 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 constants stream of views – no surprises as these are well known side effects of many 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 from Royal Free London) for some of the input below. Although I marked this with ‘Opinion’, some of it has references but I still decided to use ‘Opinion’ as the science is not yet 100%.

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’.

I always thought the gut referred to just the ‘belly’ area but in medical parlance, the gut has a 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.  NET patients should 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 they 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.

Probiotics

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 bioactive yoghurt.  I didn’t really notice any difference from either but the yoghurt was nice 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 yoghurts 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.  Nonetheless, I sense probiotics are helping and I won’t be reducing or stopping them any time soon.  If you look at several NET specific dietician/nutrition presentations, most appear to promote the use of probiotics for NET patients.

Bacteria

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 whipples, 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 which 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 diarrhoea 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 is 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 which 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.

Results:
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.

Conclusion:
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.

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

Keywords: nets, sibo, dysbiosis

My own Experience

I personally take a 5 billion dosage and am happy to recommend the source offline. However, in addition to obtaining from a reputable provider (i.e. in UK, MHRA approved supplier), there is evidence to suggest as long as it has some or all of the following strains that are widely available, they should provide benefit: Lactobaccilus plantarum, Lactobaccilus acidophilus, Lactobaccilus brevis, Bifidobacterium lactis and Bifidobacterium longum.

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?

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 which 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.

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.

Other useful links which have an association to this blog:

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

{b} Follow Tara on Twitter – CLICK HERE

{c} Watch a video of Tara presenting to a group of NET Patients – CLICK HERE

{d} Now Watch Tara answering the Q&A from patients – I enjoyed this – NET patients are very inquisitive! CLICK HERE

Thanks for listening