What’s good for your aging gut may also be good for your aging brain. The first study of its kind in twins found that taking daily protein and prebiotic supplements can improve scores on memory tests in people over the age of 60.
The findings, published last year, are food for thought, especially as the same visual memory and learning test is used to detect early signs of Alzheimer’s disease.
The double-blinded trial involved two cheap plant fiber prebiotics that are available over the counter in numerous nations around the world. Prebiotics are non-digestible consumables that help stimulate our gut microbes.
One is called [inulin], and it is a dietary fiber in the class fructan. Another is called fructooligosaccharide (FOS), and it is a plant carbohydrate often used as a natural low calorie sweetener.
Paper in Nature Communications
https://www.nature.com/articles/s41467-024-46116-y#Sec17
Ni Lochlainn, M., Bowyer, R.C.E., Moll, J.M. et al. Effect of gut microbiome modulation on muscle function and cognition: the PROMOTe randomised controlled trial. Nat Commun 15 , 1859 (2024). Effect of gut microbiome modulation on muscle function and cognition: the PROMOTe randomised controlled trial | Nature Communications
From the Methods:
The PROMOTe (effect of PRebiotic and prOtein on Muscle in Older Twins) trial was a randomised controlled trial in which twin pairs (monozygotic and dizygotic) were randomised, one twin to each study arm. Both twins consumed a protein (BCAA) supplement powder, and in one twin from each pair, this was combined with a prebiotic supplement (inulin and fructo-oligosaccharides) and in the other twin from each pair, it was combined with a placebo (maltodextrin). These pre-mixed supplements were in identical sachets, and each participant was advised to take one sachet a day for 12 weeks in a glass of water or another drink at the same time each day. We advised participants in both groups to undertake resistance exercises.
Participants were provided with sachets of food supplements in powder form. All sachets contained 3.32 g of branched-chain amino acid protein powder, consisting of L-leucine 1660 mg, L-isoleucine 830 mg, and L-valine 830 mg. The intervention arm sachets also contained 7.5 g of prebiotic (Darmocare Pre®, Bonsuvan), which consists of inulin (3.375 mg) and fructo-oligosaccharides (FOS) (3.488 mg). The placebo sachets contained 7.5 g of maltodextrin powder. All of these food supplements are available commercially without prescription.
Discussion summary
Prebiotics improved cognition but did not impact muscle strength and function, compared with placebo in a cohort of healthy older twins. Our results demonstrate that cheap and readily available gut microbiome interventions hold promise for improving cognitive frailty in our ageing population. While this trial did not demonstrate improvement in skeletal muscle strength, we showed that gut microbiome modulation via prebiotic supplementation in the context of ageing-muscle research is feasible and well tolerated, with clear responses noted in the gut microbiota composition and function. Future larger trials can examine the use of gut microbiome targeting interventions to overcome age-associated anabolic resistance. We also illustrate the feasibility of remotely delivered trials for older people, which holds promise for future studies in this area, aiming to reduce the under-representation of older people in clinical trials and reduce research costs.