Our intestinal system contains around 1.5kg of microbes (bacteria) and, in recent decades, it is becoming more and more apparent that these bacteria can have widespread effects on our physical and mental health.

There are over 1000 different species of bacteria in every person, and the make-up of each persons’ bacterial fingerprint is one of thefactorsthat effects our health. Having more or less of certain species can have positive and negative consequences, and, in general, the more diverse your bacterial composition, the better[1]. However, as we age, our the bacteria in our gut often becomes less diverse and contain less of the ‘beneficial’ bacteria [2].

That’s why, making sure to get fruit and vegetables in our diet, to increase our fibre intake, is important as we age.

Another approach to maintaining our gut health as we get older is to consider supplementing with a probiotic. Probiotics are one or more of the beneficial bacteria that you could consume, usually as a capsule. In elderly participants, supplementing with probiotics has been shown to:

-  Improve immune function, and reduce risk of illness. Furthermore, it appears that subjects with the weakest baseline responsiveness benefited the most by the probiotic supplementation [3]

-  Reduce inflammation, and increase anti-inflammatory short-chain fatty acids (SCFA) [4]. These SCFA are produced by the bacteria in our digestive system, but we typically produce less of them as we age [5].

-  Improve symptoms of constipation [6]

-  Lower the incidence of diarrhea associated with antibiotic use [7]

In general, probiotics containing more than one species appear to be more effective than those with just one species. Look for products containing species called Lactobacillus and Bifidobacterium, and for products with around 25 billion CFUs.


  1. Qin, J., et al., A human gut microbial gene catalogue established by metagenomic sequencing. Nature, 2010. 464(7285): p. 59-65.
  2. Landete, J.M., et al., Probiotic Bacteria for Healthier Aging: Immunomodulation and Metabolism of Phytoestrogens. Biomed Res Int, 2017. 2017: p. 5939818.
  3. Tiihonen, K., A.C. Ouwehand, and N. Rautonen, Human intestinal microbiota and healthy ageing. Ageing Res Rev, 2010. 9(2): p. 107-16.
  4. Macfarlane, S., et al., Synbiotic consumption changes the metabolism and composition of the gut microbiota in older people and modifies inflammatory processes: a randomised, double-blind, placebo-controlled crossover study. Aliment Pharmacol Ther, 2013. 38(7): p. 804-16.
  5. Rampelli, S., et al., Functional metagenomic profiling of intestinal microbiome in extreme ageing. Aging (Albany NY), 2013. 5(12): p. 902-12.
  6. Chmielewska, A. and H. Szajewska, Systematic review of randomised controlled trials: probiotics for functional constipation. World J Gastroenterol, 2010. 16(1): p. 69-75.
  7. Rondanelli, M., et al., Review on microbiota and effectiveness of probiotics use in older. World J Clin Cases, 2015. 3(2): p. 156-62.