Alterations of the gut microbiome have been associated with obesity and metabolic disorders. The gut microbiota can be influenced by the intake of dietary fibres with prebiotic properties, such as inulin-type fructans. The present study tested the hypothesis that obese individuals subjected for 12 weeks to an inulin-enriched v. inulin-poor diet have differential faecal fermentation patterns. The fermentation of cellulose and inulin hydrolysates of six different inulin-rich and inulin-poor vegetables of both groups was analysed in vitro on faecal inocula. The results showed that the microbiota from obese patients who received a fructan-rich diet for 3 weeks produces more gas and total SCFA compared with the microbiota taken from the same individuals before the treatment. Obese individuals fed with a low-fructan diet produce less gas and less SCFA compared with the treated group. The present study highlighted profound changes in microbiota fermentation capacity obtained by prebiotic intervention in obese individuals, which favours the production of specific bioactive metabolites.

Alternate day modified fasting (ADMF) beneficially modulates several indicators of CHD risk, but its effects on LDL particle size have never been tested. Accordingly, we examined the effects of ADMF on LDL particle size and distribution in obese adults. Sixteen obese subjects participated in a 10-week trial with three consecutive phases: (1) 2-week control phase; (2) 4-week ADMF controlled feeding phase; (3) 4-week ADMF self-selected feeding phase. After 8 weeks of diet, body weight and waist circumference were reduced (P < 0·05) by 5·6 (sem 0·9) kg and 4·0 (sem 0·9) cm, respectively. LDL-cholesterol and TAG concentrations decreased (P < 0·05) by 25 (sem 10) % and 32 (sem 6) %, respectively. Peak LDL particle size increased (P < 0·05) from 266 (sem 1) to 268 (sem 1) Å. Additionally, the proportion of small LDL particles decreased (P < 0·05) from 13 (sem 2) % to 9 (sem 3) %, while the proportion of large LDL particles increased (P < 0·05) from 68 (sem 4) % to 76 (sem 4) % post-treatment. These findings suggest that ADMF is an effective diet strategy for increasing LDL particle size and decreasing the proportion of small, dense LDL particles in obese adults.