Gut Microbiota Influences the Photoperiod Effects on Proanthocyanidins Bioavailability in Diet-Induced Obese Rats

SCOPE

Polyphenols health effects on obesity are mainly attributed to their metabolites generated after their gastrointestinal digestion, in which gut microbiota plays an important role. Moreover, gut microbiota composition and polyphenols bioavailability are influenced by differences in day light length (photoperiod). Thus, this study evaluates if a grape seed proanthocyanidins (GSPEs) extract bioavailability is influenced by different photoperiod exposure via gut microbiota modulation in an obesogenic context.

METHODS AND RESULTS

Cafeteria diet-induced obese Fischer 344 rats are housed under different photoperiod conditions (6, 12, or 18 h of light per day) during 9 weeks and administered with GSPE (25 mg kg^-1 ) or GSPE and an antibiotic cocktail (ABX) for the last 4 weeks. Serum GSPE-derived metabolites are quantified by HPLC-MS/MS.

CONCLUSION

A higher bioavailability is observed under 6 h light/18 h darkness (L6) compared to 18 h light/6 h darkness (L18). Individual metabolites, especially those from the gut microbiota, are affected by photoperiods. ABX treatment alters these photoperiod-mediated changes. Therefore, these results suggest that gut microbiota plays a key role in the photoperiod effects on GSPE bioavailability in obese rats.

The effects of grape seed proanthocyanidins in cafeteria diet-induced obese Fischer 344 rats are influenced by faecal microbiota in a photoperiod dependent manner

Polyphenols are of high interest due to their beneficial health effects, including anti-obesity properties. The gut microbiota may play an important role in polyphenol-mediated effects as these bacteria are significantly involved in the metabolism of polyphenols. Moreover, seasonal rhythms have been demonstrated to influence both the gut microbiota composition and polyphenol bioavailability. Thus, the goal of this study was to evaluate the impact of photoperiods and microbiota on polyphenol functionality in an obesogenic context. Towards this aim, cafeteria diet-fed Fischer 344 rats were housed under three different photoperiod conditions (L6: 6 h of light, L12: 12 h of light and L18: 18 h of light) for 9 weeks. During the last 4 weeks of the experiment, rats were daily administered with an oral dose of a grape seed proanthocyanidin extract (GSPE) (25 mg per kg body weight). Additionally, rats treated with GSPE and an antibiotic cocktail (ABX) in their drinking water were included for a better understanding of the gut microbiota role in GSPE functionality. Vehicle and non-ABX treated rats were included as controls. GSPE decreased body weight gain and fat depots only under L18 conditions. Interestingly, the gut microbiota composition was strongly altered in this photoperiod. GSPE + ABX-treated rats gained significantly less body weight compared to the rats of the rest of the treatments under L18 conditions. These results suggest that GSPE functionality is modulated by the gut microbiota in a photoperiod dependent manner. These novel findings corroborate seasonal rhythms as key factors that must be taken into account when investigating the effects of polyphenols in the treatment or prevention of chronic diseases.

Administration Time Significantly Affects Plasma Bioavailability of Grape Seed Proanthocyanidins Extract in Healthy and Obese Fischer 344 Rats

SCOPE

Phenolic compounds are bioactive molecules that are associated with several health benefits. Metabolization and absorption are the main determinants of their bioavailability and bioactivity. Thus, the study of the factors that modulate these processes, such as sex or diet is essential. Recently, it has been shown that biological rhythms may also play a key role. Hence, the aim of this study is to evaluate if the bioavailability of a grape proanthocyanidin extract (GSPE) is affected by the administration time in an animal model of metabolic syndrome (MetS).

METHODS AND RESULTS

Female and male Fischer 344 rats are fed either a standard or a cafeteria diet (CAF) for 9 weeks, and an oral dose of GSPE (25 mg kg^-1 ) is daily administered either at 8:00 am (zeitgeber time (ZT)-0) or at 8:00 pm (ZT-12) during the last 4 weeks. Plasma phenolic compounds are then quantified by liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Phase-II and gut microbiota-derived phenolic metabolites are affected by ZT in all conditions or only in obese rats, respectively. CAF feeding affected the bioavailability of phenolic acids and free flavan-3-ols. Differences due to sex are also observed.

CONCLUSION

These findings demonstrate that ZT, diet, and sex are key factors influencing phenolic compounds bioavailability.