Research

Mixed

Consumption of 5g/day of the human milk oligosaccharide 2'-fucosyllactose (2'-FL) for 6 weeks significantly increases the relative abundance of Bifidobacterium in the gut microbiota of healthy older adults.

For older adults looking to support gut health, consuming 5g of 2'-FL daily for 6 weeks is a well-tolerated intervention that significantly increases beneficial Bifidobacterium levels. While it did not change the primary immune score, it did increase HDL cholesterol and fasting insulin. Users should expect this effect to be reversible upon stopping supplementation.

GoodSupportsHIGH confidence
relative abundance of Bifidobacterium was significantly higher in the High Dose 2'-FL group (mean relative abundance = 9.7%, standard error (s.e.) = 1.4%) compared to the Placebo group (mean relative abundance = 3.5%, s.e. = 0.96%) at the study midpoint (Week 3)... The relative abundance of Bifidobacterium in the Low Dose 2'-FL group was not significantly different from the Placebo or the High Dose 2'-FL groups at Week 3 but was at an intermediate abundance between both groups
Matthew M. Carter et al. · medRxiv · 2023

Why this rating

Randomized controlled trial with a pre-registered primary endpoint, though the primary endpoint (cytokine response) was not met, the secondary microbiome findings are robust.

Source

A human milk oligosaccharide alters the microbiome, circulating hormones, cytokines and metabolites in a randomized controlled trial of older individuals

Matthew M. Carter et al. · medRxiv · 2023

DOI 10.1101/2023.08.18.23294085

preprint · n=89Cited 4×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →