“The results confirmed age as a key determinant of the gut microbiome, which is an important finding because it demonstrates that age should be considered when studying therapeutic treatments, such as prebiotics/probiotics, or functional foods, or when considering an approach to modify the gut microbiome using precision medicine,” scientists from the U.S. Department of Agriculture’s Agricultural Research Service, Cryptobiotix and Ghent University in Belgium, and Queen’s University Belfast in Northern Ireland in the journal Nutrients.
The positive effects of Bifidobacterium are well-researched—and it has been proven that Bifidobacterium levels decrease as people age, with the highest levels being in infancy. Previous research has shown 2’-FL to increase Bifidobacterium in infants and toddlers, generating interest in its function as a prebiotic for all age groups.
“Research has demonstrated that levels of Bifidobacterium within the gut microbiota positively corresponds with longevity and overall human health and negatively correlates with immunosenescence, metabolic disorders and other conditions such as IBS in elderly adults,” the authors wrote.
Study details
The study, completed ex vivo, included participants from six different age groups: breastfed infants, toddlers, children and adults 25 to 35 years, 35 to 50 years and 50 to 70 years. Fecal samples from each participant were analyzed and then treated with 2’-FL, fructo-oligosaccharides and lactose.
The initial analysis showed that breastfed infants and toddlers were more distinct in their gut microbiome than other age groups. After the addition of 2’-FL, there was a significant increase in Actinomycetota, due to the increase in Bifidobacteriaceae. This corresponded with a decrease in populations of Clostridiales and Peptostreptococcaceae. Some other species affected by the addition of 2’-FL included Phocaeicola dorei, Phocaeicola vulgatus, Anaerobutyricum hallii and Mediterraneibacter faecis.
“Interestingly, for all age groups, Bifidobacterium species correlated positively to acetate production,” the study noted. “Except for BF infants, B. adolescentis correlated positively with acetate, propionate and butyrate, although to varying degrees. Looking at propionate and butyrate, which are not end products of 2’-FL metabolism but were considered to have increased through cross-feeding interactions, the taxa correlated to these metabolites were highly age-dependent.”
The species of Bifidobacterium that responded to the addition of 2’FL differed depending on participant age, likely due to the age-related change in species of Bifidobacterium present and their populations prior to the study.
“Bifidobacterium species composition was age-dependent: B. longum, B. catenulatum/pseudocatenulatum and B. adolescentis were most prevalent for breastfed infants, toddlers/children and adults, respectively,” the authors wrote.
They noted that it is not possible to determine whether this effect was due to the direct metabolism of 2’-FL or cross-feeding interactions. However, the taxa enhanced by potential cross-feeding were found to also be age-dependent.
Source: Nutrients, 2025, 17(1), 151. doi: 10.3390/nu17010151. “The Bifidogenic Effect of 2’Fucosyllactose Is Driven by Age-Specific Bifidobacterium Species, Demonstrating Age as an Important Factor for Gut Microbiome Targeted Precision Medicine”. Authors: Firrman, J., et al.
