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Il microbiota intestinale contribuisce a regolare il livello dei lipidi

Migliaia di specie batteriche diverse abitano il nostro intestino e sono coinvolte nel nostro metabolismo partecipando all'utilizzo dell'energia degli alimenti, all'attivazione del sistema immunitario, al metabolismo dei farmaci ed a molti altri processi. Con la tipizzazione genica della popolazione batterica di quasi 900 soggetti, gli autori hanno potuto identificare 34 gruppi di batteri ed hanno rilevato che la ricchezza e la diversità della popolazione batterica intestinale era inversamente correlata alla massa corporea ed ai trigliceridi e direttamente correlata alle HDL, ma poco influente sul livello delle LDL e del colesterolo. Queste osservazioni potrebbero essere la base per una terapia che modificando il microbiota intestinale influisca positivamente sul quadro lipidico e sull'obesità.

The Gut Microbiome Contributes to a Substantial Proportion of the Variation in Blood Lipids

Fu J, Bonder MJ, Cenit MC, Tigchelaar EF, Maatman A, Dekens JA, Brandsma E, Marczynska J, Imhann F, Weersma RK, Franke L, Poon TW, Xavier RJ, Gevers D, Hofker MH, Wijmenga C, Zhernakova A

Circ Res. 2015;117:817-824

RATIONALE: Evidence suggests that the gut microbiome is involved in the development of cardiovascular disease, with the host-microbe interaction regulating immune and metabolic pathways. However, there was no firm evidence for associations between microbiota and metabolic risk factors for cardiovascular disease from large-scale studies in humans. In particular, there was no strong evidence for association between cardiovascular disease and aberrant blood lipid levels.
OBJECTIVES: To identify intestinal bacteria taxa, whose proportions correlate with body mass index and lipid levels, and to determine whether lipid variance can be explained by microbiota relative to age, sex, and host genetics.
METHODS AND RESULTS: We studied 893 subjects from the Life-Lines-DEEP population cohort. After correcting for age and sex, we identified 34 bacterial taxa associated with body mass index and blood lipids; most are novel associations. Cross-validation analysis revealed that microbiota explain 4.5% of the variance in body mass index, 6% in triglycerides, and 4% in high-density lipoproteins, independent of age, sex, and genetic risk factors. A novel risk model, including the gut microbiome explained = 25.9% of high-density lipoprotein variance, significantly outperforming the risk model without microbiome. Strikingly, the microbiome had little effect on low-density lipoproteins or total cholesterol.
CONCLUSIONS: Our studies suggest that the gut microbiome may play an important role in the variation in body mass index and blood lipid levels, independent of age, sex, and host genetics. Our findings support the potential of therapies altering the gut microbiome to control body mass, triglycerides, and high-density lipoproteins.

Circ Res. 2015;117:817-824