bacteria in the microbiome

Key Topic

Today we will be discussing if probiotics can help with bloating and IBS.

Probiotic Definition

  • Probiotics are defined as “live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host.”
  • To be classified as a probiotic something needs to have evidence of benefit. But that definition is often used loosely. 
  • It also does not mean that each specific strain will help each form of IBS specifically.

Mechanisms of Action

Probiotics cans help through any of the following reasons:

  • Increasing bacteria in the large intestine that are associated with reduced symptoms.
  • Decreasing the number of pathogenic bacteria that can contribute to symptoms.
  • Influencing gut-motility.
  • Helping to manage SIBO
  • Influencing the gut-brain axis.
  • Decreasing the hypersensitivity that is associated with pain from IBS.
  • Increasing the production of short-chain fatty acids such as butyrate.

Note there are mechanisms beyond this but I wanted to keep this easy for podcast content.

Research

  • We have previously spoken about research in this space, but there is even more research now.
  • The most recent meta-analysis is from 2024 and it has found that on average probiotics outperform placebo for improving IBS symptoms, so that’s positive.
  • But noting that it isn’t actually the case for everyone.
  • For example one of the more impressively beneficial studies used the strain Lactobacillus plantarum and found that 78% of participants identified an improvement. Although, that still leaves 22% where there was no benefit.
  • A lot of the other studies are less impressive. Often it seems to be ~50% of more people experiencing benefit.

Other Thoughts on the Microbiome

  • There are often noticeable differences in the microbiome between those with and without IBS.
  • It makes it half-tempting to conclude that just addressing those differences could have a huge benefit for IBS. This is where probiotics could come in.
  • For example, on average, people with IBS have lower levels of lactobacillus and bifidobacterium populations.
  • There is a strong association between a lack of bifidobacterium and IBS related pain, where those who experience pain have an average of 5x less bifidobacterium.
  • At this stage the research isn’t promising yet for individualised testing designed to help address this, but it is an interesting space.

What / How to Use

  • When explaining WHY it’s hard to give a good recommendation we point to an older review from 2016 as a good example.
  • That review was broader and included 29 studies. It found that 14 of 29 studies had positive results. Of those 14 studies, 10 different probiotics were used.
  • It’s pretty hard to say what is BEST whilst considering that.
  • Strain specificity
  • The gold standard is to do the following:
    1) Make sure that the colony forming units (CFU) count is at least 1 billion CFU per serving.

2) Make sure it contains some of the strains with more research for helping IBS such as Lactobacillus plantarum, Lactobacillus acidophilus, and Bifidobacterium infantis.

  • Theoretically multi-strain probiotics SHOULD be better, but we don’t have much research comparing that. 
  • The gold standard is to trial a product for around 12 weeks and then assess the benefit. If there was benefit, continue and if not, you can cease usage.

Summary

Probiotic recommendations are tricky because the research is still inconsistent. Unlike protein powders with well-established doses, probiotic studies vary in strains and don’t often test different doses. I recommend LifeSpace IBS Support as it aligns well with current evidence, but there’s still a lot we don’t know. That’s why we’re excited about the future of personalised gut health, with more research, tailored recommendations will become much more effective.

Relevant Blogs / Resources

Relevant studies:

Relevant Blog Posts:

Probiotic We Recommend:

LifeSpace IBS Support Probiotic