FOOD & DRINK
PREBIOTICS, PROBIOTICS AND THE MICROBIOME Priya Tew Freelance Dietitian and Specialist in Eating Disorders Priya runs Dietitian UK, a freelance dietetic service that specialises in social media and media work, consultancy for food companies, eating disorder support, IBS and chronic fatigue. She works with NHS services, The Priory Hospital Group and private clinics, as well as providing Skype support to clients nationwide.
REFERENCES Please visit the Subscriber zone at NHDmag.com
The world of prebiotics, probiotics and the microbiome has exploded lately and it is definitely an area to stay abreast of and be ready to explain to people in simple terms. There are instant dietary changes that people can make to improve their gut health, potentially their mental health and overall physical health too. The microbiome is an exciting area of research right now. It has the potential to make some big changes to how we approach nutrition. The gut microbiota is a vast and diverse community of micro-organisms in the human intestinal tract, including bacteria, viruses, archaea and unicellular eukaryotes.3 There are 10 times more microbial cells than there are human cells in the body. The diversity and number of microbes increases through the GI tract from the stomach with the colon containing the most. This is affected by the current bacterial composition (types of microorganisms) and the abundance. PREBIOTICS
Prebiotics are natural, non-digestible food components which help promote the growth of beneficial bacteria (probiotics) in the gut. They alter the colonic microbiota in favour of a healthier composition. Fermentation
in the colon leads to the production of energy, metabolites and micronutrients and an increase in probiotics. Prebiotics are found naturally in a range of fibre rich foods. These include fermentable oligosaccharides, consisting of three to 10 monosaccharide units. These foods are fermented in the large intestine, giving rise to their benefits. Examples include: • fructans found in main fruit and veg, grains legumes, nuts and inulin; • galacto-oligosaccharides (GOS) found in legumes and beans. It’s worth noting here that a different class of GOS (β-linked lactose-derived) has been shown to have multiple beneficial prebiotic properties.
Table 1: Foods which are a natural source of prebiotics Fructans
Galacto-oligosaccharides
Fruit: nectarines, watermelon, plums, pomegranate, grapefruit, ripe bananas
Legumes: chickpeas, lentils, beans
Veggies: artichokes, cabbage, onions, shallots, spring onions, leeks, garlic, asparagus, broccoli, Brussels sprouts, fennel Grains: wholewheat, rye and barley Legumes and nuts: chickpeas, lentils, beans, pistachios, cashews, almonds Other: inulin, dandelion tea www.NHDmag.com December 2018/January 2019 - Issue 140
23
WHAT TO LOOK FOR IN A PROBIOTIC A guide for healthcare professionals CHECK THE LABEL AND QUALITY
Does the label state the full strain name of the microorganism(s) in the product?
Does the label state the number of live cells of the probiotic strain(s) in the product?
NOTE: This should comprise three components: genus, species and strain identifier.
Yakult contains 1010 Lactobacillus casei Shirota per 100 ml, when refrigerated.
Genus (e.g. Lactobacillus), species (e.g. casei) and strain (e.g. Shirota) is stated in full on Yakult’s packaging.
This is equivalent to 6.5 billion live cells per 65ml bottle.
Contact the company. Are there quality control procedures in place? NOTE: This is necessary to ensure the product contains the correct strains and number of live microbial cells as stated on the label.
Yakult is acknowledged by experts to be a quality probiotic.
CHECK THE SCIENTIFIC EVIDENCE
Contact the company or access their HCP website, to find the supporting research. NOTE: (i) Regulatory restrictions mean companies can share research information with HCPs but not the general public; (ii) Not all probiotic research papers can be found on medical literature databases.
The research evidence for Lactobacillus casei Shirota can be found at www.yakult.co.uk/hcp or by contacting science@yakult.co.uk
CHECK FOR GI TRACT SURVIVAL
CHECK FOR EFFICACY OF THE STRAIN
For oral probiotics, are there human intervention trials showing survival of the probiotic strain(s) through the gut?
Check for trials and studies for the probiotic and the particular patient problem
NOTE : In vitro or model studies are not proof of gut survival in vivo.
(important for assessment of safety).
There are several research papers describing human studies showing the gut survival of Lactobacillus casei Shirota.
See expert advice in ‘LcS Insight: HCP Study Day 2014’ and ‘Your Guide to Probiotics’.
For further support on what to look for in a probiotic or to access the research behind Yakult, then please visit www.yakult.co.uk/hcp contact science@yakult.co.uk or call 020 8842 7600 This resource is intended for healthcare professionals. Not to be distributed to patients.
Table 2: Examples of fermented foods Fermented Foods Live yoghurt Kefir Aged cheeses Kimchi Sauerkraut Miso
Tempeh Sourdough bread Soy-fermented foods Fermented sausage Pickles
PROBIOTICS
Probiotics are live organisms, which when administered in adequate amounts confer a health benefit.1 These can change/repopulate the intestinal bacteria in order to rebalance the gut flora and include live cultures and fermented foods. They can stimulate the immune system and help decrease the risk of infections by affecting the balance of pathogenic and commensal bacteria. They can reduce the production of pro-inflammatory cytokines, thus counteracting inflammation and cell damage.3 FERMENTED FOODS
There has been a resurgence in the popularity of fermented foods recently. These foods are as old as humans, but we have lost some of the traditional methods from our diet culture. As soon as farming and hunting began, fermentation was used as a means of preserving food. The varieties we have now in the shops will vary widely depending on the method of manufacture, the bacterial cultures added in, plus duration of storage.7 This makes it hard to know if certain products contain enough live cultures to have a benefit. This is where it becomes tricky - how do we know there are enough live cultures in a product to be of benefit? On the other hand, at least we know they are unlikely to have a negative effect, so are worth trying. A study on retail food samples of fermented foods found many contained 105-7 cfu per g of live bacteria which was classed in the study as a ‘good amount’. However, there is no legislation on what a relevant dose is or to check that these foods contain the beneficial bacteria at all.2 The health benefits of probiotics include positives for gut health, improvements in glucose tolerance, blood lipid profiles and digestive function. However, this is evolving research and we need more RCTs to help us really see the effects.6
The phyla firmicutes and bacteroidetes make up around 90% of the bacteria in the gut; however, there are also smaller genus that have important roles and shouldn’t be forgotten, eg, Bifidobacteria and Lactobacillus. The gut microbiota influences the whole body and GI tract in various ways, including affecting gut permeability and tight junction formation. Fermentation of oligosaccharides and fibre, including beta glucans and psyllium, leads to the production of short-chain fatty acids, acetate, propionate and butyrate. These are used by the intestinal epithelial for energy and can lower the luminal pH and so inhibit pathogen growth. The production of these chemicals can also affect immunomodulation via stimulating the production of certain cytokines, inhibiting others, thus playing a role in the regulation of proinflammatory and anti-inflammatory cascades.3 GUT HEALTH STUDY
The link between gut microbe diversity and diet was investigated in more than 1500 people in an observational study. The American Gut project4 used citizen scientists, so the public donated their time and personal data for analysis. The results showed that eating 30 or more-plant based foods a week compared to 10 or less plant foods a week leads to a more diverse microbiome. Those eating more plant foods had fewer genes for antibiotic resistance in faecal samples. There was a potential positive mental health effect seen too. Those with PTSD, schizophrenia, depression, or bipolar disorder had more bacteria in common with others suffering from similar conditions than the controls, suggesting a bacterial link that could potentially be changed via diet.4 One key thing to note from this study is that diversity was key, so, eating a variety of plant foods over the week and not the same ones day in and day out is more beneficial.
www.NHDmag.com December 2018/January 2019 - Issue 140
25
FOOD & DRINK SUPPLEMENTATION
In the UK, most people do not eat enough fibre (the average intake is 17.2/day for women and 20.1g/day for men).8 The recommended average intake for adults is 30g per day. Certain supplements may be helpful to bridge the fibre gap. Regarding probiotics, many products are available, but these are often expensive, so which are the right ones to direct people to without them wasting money? This is where it gets complicated as many probiotics are strain specific. There can be several thousand strains of one species (eg, Lactobacillus) and each strain has its own unique properties and impact on the body. One big issue we face as clinicians is which probiotic to recommend. The market is huge and the evidence is very much up and coming. Telling people to just “take a probiotic” is too broad and is pretty much a lucky dip. Much of the research conducted either fails to mention the specific strains used, or pools different strains together, therefore diluting down the results. The other
complication is that formulations of probiotics can change over time. Not only is it important to look at the strain of probiotics, but also the impact a particular strain has on a disease. Obviously, there is no point recommending a strain of probiotic that is useful for diarrhoea prevention for a patient who has H. pylori infection! A recent systematic review looked at the research from 1970-2017, specifically focusing on strains and disease states.5 A total of 228 trials were included. Strong evidence was found for the efficacy of specific probiotics for six disease states: antibiotic associated diarrhoea (AAD), clostridium difficile infections (CDI), IBD, IBS, traveller’s diarrhoea (TD), acute paediatric diarrhoea, as well as for H. pylori infections. The strongest evidence was found for the VSL#3 mixture (B. breve BB02, B. longum BL03, B. infantis BI04, L. acidophilus BA05, L. plantarum BP06, L. paracasei BP07, L. helveticus BD08, Strept thermophiles BT01). There were six trials with significant efficacy for the treatment of IBD.
dieteticJOBS.co.uk
Good health depends on a balanced gut
• Quarter page to full page • Premier & Universal placement listings • NHD website, NH-eNews and Network Health Digest placements
To place an ad or discuss your requirements please call (local rate)
01342 824073
dieteticJOBS.co.uk
26
www.NHDmag.com December 2018/January 2019 - Issue 140
Bimuno® naturally increases good bacteria in your gut in iust 7 days• • Bimuno is a daily prebiotic supplement • Helps with digestive discomfort • Suitable to be used alongside a low FODMAP diet
s1muno'v'
e1mund
Available from Boots, Holland & Barrett and at www.bimuno.com For more information please contact hcp@bimuno.com 'Scientific data shows that daily use of Bimuno® increases gut bifidobacteria levels within 7 days, results may vary.
Table 3: Strength of efficacy for probiotics with identified strain designations and at least two randomised controlled trials with significant findings for the prevention or treatment of disease5 Net ≥ 2 significant randomised clinical trials (RCTs) (number of significant RCTs/nonsignificant RCTs)
At least two RCTs with significant efficacy (number of significant RCTs/non-significant RCTs)
Prevention AAD
Saccharomyces boulardii I-745 (11+/6−) Lactobacillus acidophilus CL1285+ Lactobacillus casei LBC80R+ Lactobacillus rham-nosus CLR2 (4+/0)a L. casei DN114001 (2+/0−)
Enterococcus faecalis SF68 (2+/1−) L. rhamnosus GG (2+/4−) Lactobacillus reuteri 55730 (2+/1−)
Paid AAD
S. boulardii I-745 (7+/3−)
L. helveticus R52 + L. rhamnosus R11 (2+/1−)
CDI-primary
None
L. acidophilus CL1285 + L. casei LBC80R + L. rhamnosus CLR2 (2+/2−)a
Nosocomial infections
None
L. rhamnosus GG (2+/2−)
Traveller’s diarrhoea
S. boulardii I-745 (2+/0−)
Treatment Paediatric acute diarrhea
S. boulardii I-745 (25+/4−) L. rhamnosus GG (12+/3−) L. reuteri DSN 17938 (3+/0−) L. acidophilus LB (3+/1−) L. casei DN114001 (3+/0−) VSL#3b (2+/0−) Bac. clausii OC/SN/R (3+/1−)
L. helveticus R52 + L. rhamnosus R11 (2+/1−)
Irritable bowel syndrome
B. infantis 35624 (2+/0−) L. rhamnosus GG (2+/2−) L. plantarum 299v (4+/1−) S. boulardii I I-745 (2+/2−)
L. rhamnosus GG+ L. rhamnosus VSL#3b (2+/2−) LC705 + B. breve Bb99 + Prop. freudenreichii shermanii Jc (2+/0−)
Helicobacter pylori eradication
L. helveticus R52 + L. rhamnosus R11 (4+/1−)
S. boulardii I-745 (5+/11−) L. reuteri 55730 (2+/2−) L. acidophilus La5 + B. animalis spp. lactis Bb12 (3+/2−)
Inflammatory bowel disease
VSL#3b (8+/2−)
S. boulardii I-745 (2+/1−)
CDI-recurrences
S. boulardii I-745 (2+/0−)
Disease indication
AAD, antibiotic-associated diarrhoea; B., Bifidobacterium; Bac, Bacillus; CDI, clostridium difficile infections; E. Enterococcus; L. Lactobacillus; Prop. Propionibacterium; S. saccharomyces. a Includes two dose treatment arms from one trial. b VSL#3, a mix of eight strains (B. breve, B. longum, B. infantis, L. acidophilus, L. plantarum, L. paracasei, L. debrueckii spp. bulgaricus, and Streptococcs thermophilus).
TAKE HOME MESSAGES
1 Encourage people to eat a diverse amount of plant-based foods. Variety is key. This doesn’t have to mean that they go vegetarian or vegan, but just the message of eating more plant foods every day. 30 or more plant foods may seem a lot in a week, but everyone can start by increasing from where they are, adding five different portions a week. 2 Prebiotic foods are plentiful and link into the message of eating more plant-based foods. Using the message that these foods are prebiotics may encourage some people to eat more of them. 3 Fermented foods may be a useful source of probiotics. Adding live yoghurt and pickles can be a simple way to do this. 4 When recommending probiotic supplements for disease states, check the evidence for the specific strains that work. www.NHDmag.com December 2018/January 2019 - Issue 140
27