Impact of maternal intermittent fasting during pregnancy on cardiovascular, metabolic and renal function in adult rat offspring

Inverted day-night feeding during pregnancy affects the brain health of both maternal and fetal brains through increasing inflammation levels associated with dysbiosis of the gut microbiome in rats

BACKGROUND

In both humans and rodents, inappropriate feeding times during pregnancy can cause maternal metabolic abnormalities, increasing the risk of neurodevelopmental disorders in both the mother and offspring. Using a rat model, this study investigates whether feeding only during the inactive phase in rats leads to anxiety-like behaviors and abnormal brain development in fetuses through gut microbiota imbalance.

METHODS

10-week-old female rats in the inactive-phase feeding group (IF group) were first trained for daytime feeding, ensuring that energy intake was statistically insignificant and different from that of the normal diet feeding group (ND group). They were then paired with male rats, and the previous feeding regimen was continued after pregnancy. Anxiety-like behavior was evaluated using the open-field test. Maternal caecal microbiota was analyzed using 16S rRNA sequencing. Enzyme-linked immunosorbent assay (ELISA) measured serum inflammation factors. RT-PCR was employed to assess mRNA levels of integrity genes and inflammatory cytokines in the maternal hippocampi, intestines, fetal brains, and placentae.

RESULTS

There were no statistically significant differences in energy intake or body weight gain between the IF and ND groups. In the open field test, dams in the IF group exhibited anxiety-like behavior, as indicated by fewer entries into and shorter duration in the central zone. Active-phase fasting elevated maternal serum inflammatory cytokine levels and impaired antioxidant capacity. It also increased intestinal permeability and induced gut microbiota dysbiosis, characterized by a decrease in Akkermansia and an increase in Dubosiella. Changes in the expression of intestinal circadian genes and elevated intestinal inflammatory cytokines were observed. Lipopolysaccharide (LPS) translocated into the maternal circulation, activated Toll-like receptor 4 (TLR 4), and passed through the compromised placental barrier into the fetal brain, leading to increased expression of inflammatory cytokines in the fetal brain.

CONCLUSIONS

The misalignment between maternal feeding time and the biological clock during pregnancy disrupts the balance of the gut microbiota and peripheral rhythms. The impaired intestinal and placental barriers allow LPS from the gut to infiltrate the maternal hippocampus and fetal brain, increasing inflammation and impacting both maternal and fetal brain health.

Impact of preconceptional intermittent fasting on reflex ontogenesis, physical and somatic development of the offspring of Wistar rats

BACKGROUND

Intermittent fasting (IF) has health benefits; however, little is known about its effects on the offspring when practiced by dams in the preconception period. The aim of the study was to evaluate the impact of IF during the preconception period on physical and somatic parameters, as well as on the reflex ontogenesis of Wistar rat offspring.

METHODS

The female rats were randomized into two groups: control (CG) and intermittent fasting group (IF) submitted to a feed restriction of 16 h for four weeks during the preconception period. Reproductive performance, body weight, and energy intake were evaluated in dams. Reflex ontogeny, physical and somatic development, brain fatty acids and the brain histology were evaluated in the offspring.

RESULTS

IF did not change the reproductive performance or weight of dams during the preconception period. An acceleration of vibrissae placing and negative geotaxis parameters of reflex ontogenesis was observed, as well as anticipation of the following physical development indicators: ear unfolding, an eruption of upper incisor teeth, and inferior teeth in the IF offspring. Although the nervous tissue did not present histological changes, the content of some brain fatty acids was found in greater amounts in the IF offspring such as dihomo-γ-linolenic acid (0.66 ± 0.01 %) and eicotrienoic acid (0.58 ± 0.03 %).

CONCLUSION

IF during preconception did not change the body weight or reproductive performance of the dams, and promoted beneficial effects on the neurodevelopment of the offspring in the early life.

Impact of Parental Time-Restricted Feeding on Offspring Metabolic Phenotypic Traits

Intermittent fasting (IF) is widely recognized for its numerous health benefits, yet its impact on metabolic health across generations remains relatively unexplored. This study investigates the intergenerational effects of parental IF, specifically through 8-hour daily time-restricted feeding, on the metabolic health of offspring. By examining four different combinations of parental mating groups, we demonstrate that parental IF can influence offspring metabolic health in distinct ways. Our results reveal that parental IF conferred significant metabolic advantages compared to ad libitum (AL) feeding. IF parents exhibited lower glucose, HbA1c, cholesterol, and CRP levels, and higher ketone levels compared to AL parents. Offspring of IF-exposed animals displayed sex-specific metabolic benefits when challenged with a high-fat, high-sugar, and high-salt (HFSS) diet. Notably, female offspring from IF parents were protected against HFSS-induced glucose intolerance and exhibited lower plasma glucose levels and higher ketone levels compared to offspring of ad libitum-fed parents. Additionally, female offspring from IF parents on a HFSS diet, along with both female and male offspring on a normal diet, had elevated plasma insulin levels. Furthermore, male offspring from IF parents on a normal diet exhibited a significant reduction in body weight compared to offspring from AL parents. These findings suggest that parental IF can impart enduring metabolic benefits to offspring and may serve as an effective strategy to mitigate the risks of obesity and diabetes in future generations.

Comparative Impact of Alternate-Day Fasting and Time-Restricted Feeding on Placental Function and Fetal Development in Maternal Obesity

BACKGROUND

Maternal obesity detrimentally affects placental function and fetal development. Both alternate-day fasting (ADF) and time-restricted feeding (TRF) are dietary interventions that can improve metabolic health, yet their comparative effects on placental function and fetal development remain unexplored.

OBJECTIVES

This study aims to investigate the effects of ADF and TRF on placental function and fetal development during maternal consumption of a high-fat diet (HFD).

METHODS

One hundred 8-week-old female mice were assigned to one of four dietary regimens: (1) normal diet with ad libitum feeding (NA); (2) HFD with ad libitum feeding (HA); (3) HFD with ADF (HI); and (4) HFD with TRF (HT), administered both before and during pregnancy. On gestational day 18.5, serum and placental samples were collected from both mothers and fetuses to examine placental function and fetal development.

RESULTS

During gestation, both ADF and TRF substantially alleviated the metabolic impairments caused by an HFD in obese maternal mice. TRF mice demonstrated enhanced placental nutrient transport and fetal development, associated with reduced endoplasmic reticulum (ER) stress and inflammatory responses. In contrast, ADF markedly intensified placental stress and inflammatory responses, diminished placental nutrient transport efficiency, and consequently induced fetal growth restriction.

CONCLUSIONS

Both ADF and TRF during pregnancy significantly mitigated metabolic impairments in obese dams on an HFD. TRF mice demonstrated enhanced placental nutrient transport and fetal development, associated with reduced endoplasmic reticulum (ER) stress and inflammatory responses. In contrast, ADF markedly intensified placental stress and inflammatory responses, diminished placental nutrient transport efficiency, and consequently induced fetal growth restriction.

Nutritional requirements in pregnancy and lactation

Optimal nutrition during pregnancy and lactation is vital for the health of the mother and fetus. Nutritional needs should begin in the preconception period, as the fetus depends on the placenta for essential nutrients required for growth and development. A balanced diet rich in nutrient-dense foods-such as whole grains, vegetables, fruits, dairy, legumes, fish, and lean meats-is essential to meet caloric needs during pregnancy. Assessment of maternal health, including dietary history and micronutrient status, is critical to identify potential risks and ensure adequate nutrition. The increased need for micronutrients must be met to prevent complications and fetal growth. Exclusive breastfeeding is recommended for the first six months, and continued breastfeeding is recommended throughout the first year and beyond. During pregnancy and lactation, calorie intake should be increased by focusing on protein and healthy fats. The composition of breast milk is adapted during the breastfeeding period, so that it can provide the necessary nutrients for the growth of the infant. Personalized nutrition plans, developed in consultation with health care professionals, are critical to optimizing maternal and infant health outcomes. This manuscript supports the importance of comprehensive nutritional strategies during pregnancy and lactation to reduce risks and support healthy growth and development of mother and child.

Effects of Intermittent Fasting on Female Reproductive Function: A Review of Animal and Human Studies

PURPOSE OF REVIEW

Intermittent fasting has gained significant attention, yet a comprehensive understanding of its impact on female reproductive health is lacking. This review aims to fill this gap by examining various intermittent fasting regimens and their effects on female reproductive function, along with potential mechanisms.

RECENT FINDINGS

In healthy non-overweight/obese or pregnant animal models, alternate-day fasting (ADF) and an 8-h time-restricted feeding (TRF) window may have adverse effects on reproductive function. However, these regimens show potential to mitigate negative consequences induced by a high-fat diet (HFD) or environmental exposure. A 10-h TRF demonstrates benefits in improving fertility in both normal-weight and HFD-fed animal models. In women with overweight/obesity or polycystic ovary syndrome (PCOS), the 5:2 diet and TRF significantly reduce the free androgen index while elevating sex hormone binding globulin, promising improvements in menstrual regulation. For pregnant Muslim women, available data do not strongly indicate adverse effects of Ramadan fasting on preterm delivery, but potential downsides to maternal weight gain, neonatal birthweight, and long-term offspring health need consideration. Factors linking intermittent fasting to female reproductive health include the circadian clock, gut microbiota, metabolic regulators, and modifiable lifestyles. Drawing definitive conclusions remains challenging in this evolving area. Nonetheless, our findings underscore the potential utility of intermittent fasting regimens as a therapeutic approach for addressing menstruation irregularities and infertility in women with obesity and PCOS. On the other hand, pregnant women should remain cognizant of potential risks associated with intermittent fasting practices.

Treatment of mice with maternal intermittent fasting to improve the fertilization rate and reproduction

Maternal intermittent fasting (MIF) can have significant effects on several tissue and organ systems of the body, but there is a lack of research on the effects on the reproductive system. So, the aim of our study was to analyze the effects of MIF on fertility. B6C3F1Crl (C57BL/6N × C3H/HeN) male and female mice were selected for the first part of the experiments and were analyzed for body weight and fat weight after administration of the MIF intervention, followed by analysis of sperm counts and activation and embryo numbers. Subsequently, two strains of mice, C57BL/6NCrl and BALB/cJRj, were selected and administered MIF to observe the presence or absence of vaginal plugs for the purposes of mating success, sperm and oocyte quality, pregnancy outcome, fertility status and in vitro fertilization (IVF). Our results showed a significant reduction in body weight and fat content in mice receiving MIF intervention in B6C3F1Crl mice. Comparing the reproduction of the two strains of mice. However, the number of litters was increased in all MIF interventions in C57BL/6NCrl, but not statistically significant. In BALB/cJRj, there was a significant increase in the number of pregnant females as well as litter size in the MIF treatment group, as well as vaginal plugs, and IVF. There was also an increase in sperm activation and embryo number and the MIF intervention significantly increased sperm count and activation. Our results suggest that MIF interventions may be beneficial for reproduction in mice.

Intermittent fasting and longevity: From animal models to implication for humans

In recent years, intermittent fasting (IF) and its numerous modifications have been increasingly suggested as a promising therapy for age-related problems and a non-pharmacological strategy to extend lifespan. Despite the great variability in feeding schedules that we describe in the current work, underlying physiological processes are the same and include a periodic switch from glucose metabolism (generated by glycogenolysis) to fatty acids and fatty acid-derived ketones. Many of the beneficial effects of IF appear to be mediated by optimization of energy utilization. Findings to date from both human and animal experiments indicate that fasting improves physiological function, enhances performance, and slows aging and disease processes. In this review, we discuss some of the remarkable discoveries about the beneficial effects of IF on metabolism, endocrine and cardiovascular systems, cancer prevention, brain health, neurodegeneration and aging. Experimental studies on rodent models and human investigations are summarized to compare the outcomes and underlying mechanisms of IF. Metabolic and cellular responses triggered by IF could help to achieve the aim of preventing disease, and maximizing healthspan and longevity with minimal side effects.

Treadmill Exercise Reverses the Adverse Effects of Intermittent Fasting on Behavior and Cortical Spreading Depression in Young Rats

Intermittent fasting (IF) and physical exercise (PE) have beneficial psychological and physiological effects, improving memory and anxiety-like behavior. However, the impact of this combination on brain electrophysiological patterns is unknown. We aimed to evaluate the behavior and parameters of a brain excitability-related phenomenon named cortical spreading depression (CSD) in young rats (31-87 days of life) submitted to IF and treadmill PE for eight weeks. Sixty-four male and female Wistar rats aged 24 days were randomized into control, IF, PE, and IF+PE groups. Behavioral tests (open field (OF), object recognition, and elevated plus maze (EPM)) were performed, and the CSD propagation features were recorded. IF caused behavioral responses indicative of anxiety (lower number of entries and time spent in the OF center and EPM open arms). IF also reduced the discrimination index for object recognition memory tests and increased the propagation velocity of CSD. PE rats displayed more entries into the OF center and lowered CSD propagation speed. Data suggest that IF worsens anxiety-like behavior and memory and accelerates CSD in young rats. In contrast, PE reverted the unfavorable effects of IF. The brain effects of IF and PE at younger ages are recommended for study.