'Optimising Gut Health with Personalised Prebiotics'

1. Can you explain low and slow introduction of prebiotic with an example please?
Introducing supplements that can have an impact on the gut ecosystem can sometimes trigger short-term digestive symptoms, especially in sensitive individuals. For this reason, it can be helpful to introduce prebiotics at a lower dose as this can help to reduce those initial symptoms that might otherwise deter a client from continuing with their plan. For example, the recommended dose of Invivo Bio.Me PHGG is 5g (approx. 3 tsp) daily, but it can be a good idea to start with 1 teaspoon daily to gauge individual tolerance and increase this gradually over a few days.

2. Can you also share the site of fermentation of the prebiotics, please?
Most prebiotics resist digestion in the stomach and small intestine and therefore reach the colon intact, where they are fermented by the gut microbiota. However, the primary site of fermentation within the colon varies depending largely on molecular size and structure of the prebiotic.
Rapidly fermentable, low–degree-of-polymerisation carbohydrates such as FOS, GOS, short-chain inulin, and lactulose are typically fermented predominantly in the proximal colon. In contrast, more complex or higher-molecular-weight fibres, including long-chain inulin, partially hydrolysed guar gum (PHGG), acacia gum, oat β-glucans, and arabinoxylans, are fermented more slowly and can therefore persist into the transverse and distal colon, contributing to saccharolytic fermentation further along the large intestine.

3. Are there side effects, allergic reactions or anaphylaxis with prebiotics?
Prebiotics are generally well-tolerated but if anyone has a known allergy then they should always check the label for allergen information in any case. Some prebiotics are derived from dairy such as GOS, for example, so would not be suitable for those with a dairy allergy. Other common side effects that are not linked to allergies can include bloating and wind, but this can often be avoided by using a low and slow approach when introducing prebiotics. If you are unsure about whether specific prebiotic supplements are suitable for your client, you are welcome to contact the Clinical Team for advice.

4. Did I miss the probiotic recommendation for general gut health?
The webinar focused on prebiotics (rather than probiotics), and in particular the benefits of personalisation, rather than generalised recommendations.
If microbiome testing results are not available and you do not experience digestive symptoms, a practical approach is to obtain prebiotics from a wide variety of plant foods that naturally contain different types of fermentable fibres. This helps provide substrates for a broad range of microbes and can support overall microbiome diversity.
If someone prefers to use a supplement, it may be helpful to choose prebiotics that are utilised by a wide range of commensal microbes, such as partially hydrolysed guar gum (PHGG), inulin-type fructans, resistant starch, or arabinoxylan-containing fibres. These fibres are fermented by multiple microbial groups and/or can support cross-feeding interactions within the gut microbiota.

5. Which invivo test did you use?
The test used in the case study was Microba’s Microbiome Explorer – Comprehensive.
Microba is Invivo’s sister brand, which now covers all of our gut health and microbiome testing.

6. So if methane was present you would not suggest cooked and cooled potatoes?
Resistant starch (RS) has been shown in some intervention studies to increase intestinal methane production, particularly when provided as concentrated RS supplements.
For example, supplementation with RS2 (14–19 g/day from RS-enriched bread rolls for 7 days in Hughes et al., 2021, or ~28 g/day native amylomaize RS2 in Van Munster et al., 1994) has been associated with increased methane output in individuals with methanogenic microbiota.
However, these studies used relatively high doses of isolated RS, which may not reflect typical intake from whole foods. Therefore, the recommendation is not that individuals with methane-producing microbiomes avoid resistant-starch–containing foods such as cooked-and-cooled potatoes or other starchy foods altogether.
Instead, the guidance is to be mindful of excessive intake of RS-rich foods, particularly in large quantities or frequent servings, as this could potentially contribute to increased fermentation and methane production in susceptible individuals and exacerbate symptoms.

7. Why would someone not tolerate phgg even at low dose? My client got so bloated/ full and constipated from it on about 1/4 tsp over about 4 days
Some individuals can be very sensitive and need the gentlest approach. For these people, it can be helpful to introduce incredibly slowly, even starting at the tiniest pinch of PHGG every other day. HCPs are always welcome to book a call with the Clinical Team if they would like to discuss individual cases in more detail.