Gut supplements nudged cholesterol in type 2 diabetes, but only nudged

Type 2 diabetes is described by the authors as a global health challenge with rising prevalence, and keeping blood fats under control is one of the key elements of managing it. Alongside standard care, supplements that target the gut microbiome, meaning prebiotics, probiotics and synbiotics, have been proposed as a way to improve lipid profiles. Individual pooled analyses on this question already existed, but their findings needed to be weighed together in one place. This umbrella review set out to do exactly that.

The researchers searched three international databases, PubMed, Scopus and Web of Science, from inception up to April 2023, looking for meta-analyses of randomised trials testing microbiome-targeted therapy on the lipid profile of people with type 2 diabetes. Two researchers independently extracted the data from the relevant analyses. The outcomes were total cholesterol, triglycerides, LDL and HDL cholesterol. Various subgroup analyses were then run to work out where differences between the underlying studies came from.

Microbiome-targeted therapy showed statistically significant but small effects on every measure: effect sizes of 0.092 for total cholesterol, 0.109 for triglycerides and 0.036 for LDL, all in the favourable direction, alongside a 0.109 improvement in HDL. By the authors' account, HDL saw the greatest impact, followed by triglycerides, total cholesterol and then LDL. In the subgroup analysis, probiotics showed the most substantial effect on all lipid biomarkers of the three supplement types. Nothing recorded here reached a magnitude that would count as a large effect.

This overview pulls together existing pooled evidence rather than adding new trials, which makes it a useful snapshot of where the field currently stands. It supports the idea that gut-targeted supplements can nudge blood fats in people with type 2 diabetes, and the authors go as far as recommending them as an adjunctive option. The small effect sizes, though, keep the practical significance in question, and the abstract reports no participant totals, doses or durations. Head-to-head comparisons against established lipid-lowering treatment remain absent.

If you live with type 2 diabetes, this is a reason to see probiotic and similar supplements as a possible small helper for cholesterol and triglyceride numbers, with probiotics the strongest performer of the three types tested. It is not evidence that they rival established lipid treatment, and the shifts recorded were small on every measure. Worth knowing before anyone pitches a gut supplement as a cholesterol fix.