Can probiotics improve your health in later life?
Probiotics can make a modest contribution in later life, but which product works best depends on what you want to improve. For cognitive health there are early positive results; convincing large-scale evidence is still lacking.
Yes, probiotics can make a modest contribution to your health in later life, but which one you choose depends on what you want to improve.
The bacteria in your gut change gradually as you age. The beneficial bacteria decline and the harmful ones increase. This is linked to a low-grade inflammation in the body, loss of muscle mass, and a greater risk of infections. Dozens of studies in people show this pattern, although most are short snapshots in time.
For cognition and mood in healthy older adults, there are early signals. In a study of 63 healthy adults aged 65 and over, twelve weeks of a capsule containing Bifidobacterium bifidum BGN4 plus Bifidobacterium longum BORI improved mental flexibility and lowered stress scores compared with a dummy capsule; a protein that supports brain function also increased. If you want to try this, check the label carefully: both strains must be listed by name, along with the number of live bacteria in CFU. The advice is to keep it up for at least 12 weeks. The exact dose needed cannot be determined from the study. Having 'Bifidobacterium' on the label in general terms is not enough: the specific strain names are what matter. In a second study of 169 middle-aged and older adults, three months of LGG probiotics led to changes in gut bacteria that were associated with better cognition scores, but only in people with mild thinking difficulties, and the researchers stress that this result still needs to be repeated.
There are also encouraging signals for fewer respiratory infections, a better response to vaccinations, lower LDL cholesterol (the 'bad' cholesterol), and better blood sugar processing. However, how large these effects are varies considerably from product to product and from person to person. Whether probiotics extend your life or slow ageing has never been shown in people: that has only been looked at in animal studies. The same applies to an effect on skin ageing via the gut: an interesting idea, but not yet proven in people. For memory and thinking ability in healthy older adults, the evidence is too limited for a firm recommendation. If you still want to try it, this is the most studied avenue.
This answer is based on two small studies in older adults (63 and 169 participants respectively), a review combining 27 studies in people, several broader review studies, and one animal study. The two studies in people are too small to draw definitive conclusions; the review studies describe associations but cannot prove cause and effect. The animal study has not yet been repeated in people. The evidence for cognitive and mental effects is tentatively positive but limited; for heart and metabolic outcomes there is more evidence, but the literature is heterogeneous.
Do prebiotics work just as well as probiotics?
Prebiotics and probiotics are comparably effective for constipation; for depression and blood sugar, probiotics have a slight advantage, though the effects are small. Focus first on getting more fibre through ordinary food.
Do probiotic pills actually help your gut?
Probiotics genuinely help, but not for everything and not equally with every pill. The evidence is strongest for antibiotic-associated diarrhoea and irritable bowel syndrome; for Crohn's disease they demonstrably do not work.
How does your microbiome influence your health and longevity?
Your gut flora changes over the years and is associated with inflammatory processes, immune function and possibly how long you stay healthy. Probiotics may offer modest help with infections and vaccine response in older age, but lifespan extension has not been proven.
What is the difference between probiotics and postbiotics?
Probiotics contain live bacteria; postbiotics work with inactivated micro-organisms or their building blocks. Postbiotics are more stable and carry none of the risks associated with live bacteria.
How many probiotics do you need per day?
For irritable bowel syndrome, 1 to 4 billion live bacteria per day, maintained for at least four to eight weeks, has been shown to work. How long you keep it up is more important than the exact amount.
Can your gut microbiome influence how long you live?
There are clear indications that the composition of your gut microbiome is associated with how long and how healthily you age, but whether modifying your microbiome extends your life has not yet been demonstrated in humans.