The desynchronization of physiological and behavioral mechanisms influences the gut microbiota and eating behavior in mammals, as shown in both rodents and humans, leading to the development of pathologies such as Type 2 diabetes (T2D), obesity, and metabolic syndrome. Recent studies propose resynchronization as a key input controlling metabolic cycles and contributing to reducing the risk of suffering some chronic diseases such as diabetes, obesity, or metabolic syndrome. In this analytical review, we present an overview of how desynchronization and its implications for the gut microbiome make people vulnerable to intestinal dysbiosis and consequent chronic diseases. In particular, we explore the eubiosis–dysbiosis phenomenon and, finally, propose some topics aimed at addressing chronotherapy as a key strategy in the prevention of chronic diseases.

Introduction: Consuming hypercaloric diets during pregnancy induces metabolic, immune, and maternal intestinal dysbiosis disorders. These conditions are transferred to the offspring through the placenta and breastfeeding, increasing susceptibility to metabolic diseases. We investigated the effect of L. rhamnosus GG supplementation on offspring maternally programmed with a hypercaloric diet. Methods: Our study involved sixteen female Wistar rats aged ten weeks, which were divided into four groups based on their diets: control (Ctrl), cafeteria (CAF), control + probiotic (PRO), and cafeteria + probiotic (CPRO). The control + probiotic and cafeteria + probiotic groups received a daily oral administration of 250 μL of L. rhamnosus GG cell suspension (equivalent to 10⁹ UFC) for nine weeks. The body weight of the animals was recorded weekly, and their food intake was monitored every 24 h. An oral glucose tolerance test was conducted on the offspring at seven weeks of age. At the ninth week of age, animals were euthanized, and blood, tissues, and organs were collected. Results: Maternal supplementation with L. rhamnosus GG decreased food intake and the average birth weight, improved glucose sensitivity, and lowered the levels of LDL, cholesterol, triglycerides, and mesenteric adipose tissue in offspring compared with the control and cafeteria groups. Conclusions: Our findings indicate that supplementing with LGG during maternal programming could protect offspring from metabolic disruptions caused by a hypercaloric maternal diet.

The suprachiasmatic nucleus (SCN) is the master regulator of the circadian system, modulating the daily timing of physiological and behavioral processes in mammals. While SCN synchronization is primarily driven by environmental light signals, sex hormones, particularly androgens, have a crucial role in regulating behavioral and reproductive processes to align with daily or seasonal cycles. SCN cell populations express receptors for sex steroid hormones, contributing to circadian synchronization mechanisms. Specifically, the activation of androgen receptors in the SCN has been shown to modulate clock gene expression and influence circadian rhythms. Rabbits, widely used in experimental research, exhibit unique behavioral patterns, including plasticity in circadian typology and seasonal variations in testosterone secretion. In this study, we explored, in male rabbits, the effect of castration on the daily pattern of locomotor activity and the expression of the clock protein PERIOD 1 (PER1) in the SCN. Our results show that castration significantly reduces daily locomotor activity and PER1 expression in the SCN. Moreover, a 4 h delay in the acrophase of PER1 expression was observed. We conclude that androgens have an important role in SCN synchronization mechanisms, contributing to the organization of physiological and behavioral events in this species.