Paternal Methyl Donor Supplementation in Rats Improves Fertility, Physiological Outcomes, Gut Microbial Signatures and Epigenetic Markers Altered by High Fat/High Sucrose Diet

The positive impact of targeted modulating food intolerance on immune-related recurrent pregnancy loss

BACKGROUND

It has been proven that immune disorders are one of the vital risk factors of recurrent pregnancy loss (RPL), and the presence of food intolerance seems to play an essential role in this. However, the impact of immune status induced by food intolerance on RPL has not been reported. This study utilized a targeted diet avoiding food intolerance as much as possible for each participant to investigate their effects on pregnancy outcomes in RPL patients with positive autoimmune markers.

METHODS

From January 2020 to May 2021, fifty-eight patients with RPL were enrolled. They were divided into two groups based on the presence of autoantibodies: the autoantibody-positive group (AP, n = 29) and the autoantibody-negative group (AN, n = 29). Their food-specific immunoglobulin (Ig) G antibodies for 90 foods were tested using enzyme-linked immunosorbent assay (ELISA). The levels of immune parameters and the presence of gastrointestinal discomforts (diarrhea or constipation, eczema, and mouth ulcers) were recorded before and after dietary conditioning, followed by the analysis of pregnancy outcomes.

RESULTS

Compared to the AN group, the patients in the AP group showed immune disorders at baseline, such as reduced levels of IL-4 and complement C3, and increased levels of IL-2 and total B cells. These parameters within the AP group were significantly improved after dietary conditioning that avoided food intolerance, while no significant changes were observed in the AN group. Patients in the AP group had significantly higher food-specific IgG antibodies for cow's milk (89.66% vs. 48.28%, p < .001), yolk (86.21% vs. 27.59%, p < .001), bamboo shoots (86.21% vs. 44.83%, p < .001) compared to those in the AN group. Additionally, gastrointestinal discomforts including diarrhea or constipation, eczema, and mouth ulcers were more common in the AP group than in the AN group. After 3-month dietary conditioning, these significantly improved characteristics were only observed in the AP group (p < .001). Finally, the baby-holding rate was higher in the AP group compared to the AN group (p < .05).

CONCLUSIONS

The RPL patients in the AN group did not exhibit immune disorders, whereas those in the AP group experienced immune disorders and gastrointestinal discomforts. For patient with positive autoantibodies, dietary intervention may mitigate immune disorders and gastrointestinal discomforts, presenting a promising approach to enhance pregnancy outcomes.

Suppression of colon cancer growth by berberine mediated by the intestinal microbiota and the suppression of DNA methyltransferases (DNMTs)

The purpose of this study was to demonstrate the regulatory effect of berberine (BBR) on the intestinal microbiota and related epigenetics during the inhibition of colon cancer cell growth in vitro and in vivo. We used a nude mouse xenograft model with HT29 colon cancer cells to establish and divide into a model group and BBR group. The mice were treated for four weeks, and HT29 cells in the BBR group were cultured for 48 h. Cetuximab and the DNA transmethylase (DNMT) inhibitor 5-AZA-dC were added to HT29 cells. Tumour volume and weight were measured by hematoxylin-eosin (HE) staining for histopathological observation. Mouse faeces were collected, and the gut microbiota was analysed with 16S rDNA amplicons. The levels of cytokines in the supernatant of HT29 cells were measured by ELISA. A CCK-8 kit was used to examine the proliferation of HT29 cells, and RT‒PCR was used to measure the levels of c-Myc, DNMT1, DNMT3A, and DNMT3B. We found that BBR reduced the growth of colon cancer cells to a certain extent in vitro and in vivo, although the difference was not statistically significant compared with that in the model group. BBR significantly mediated the abundance, composition and metabolic functions of the intestinal microbial flora in mice with colon cancer. The effect of BBR on inflammatory cytokines, including IL-6, FGF, and PDGF, was not obvious, but BBR significantly downregulated IL-10 levels (P < 0.05) and reduced c-Myc, DNMT1, and DNMT3B levels (P < 0.05). Inhibiting DNMTs with 5-AZA-dC significantly suppressed the proliferation of HT29 cells, which was consistent with the effect of BBR. The inhibitory effect of berberine on colon cancer is related not only to the intestinal microbiota and its metabolic functions but also to the regulation of DNMTs.

The Gut Microbial Regulation of Epigenetic Modification from a Metabolic Perspective

Obesity is a global health challenge that has received increasing attention in contemporary research. The gut microbiota has been implicated in the development of obesity, primarily through its involvement in regulating various host metabolic processes. Recent research suggests that epigenetic modifications may serve as crucial pathways through which the gut microbiota and its metabolites contribute to the pathogenesis of obesity and other metabolic disorders. Hence, understanding the interplay between gut microbiota and epigenetic mechanisms is crucial for elucidating the impact of obesity on the host. This review primarily focuses on the understanding of the relationship between the gut microbiota and its metabolites with epigenetic mechanisms in several obesity-related pathogenic mechanisms, including energy dysregulation, metabolic inflammation, and maternal inheritance. These findings could serve as novel therapeutic targets for probiotics, prebiotics, and fecal microbiota transplantation tools in treating metabolic disruptions. It may also aid in developing therapeutic strategies that modulate the gut microbiota, thereby regulating the metabolic characteristics of obesity.

A systematic scientometric review of paternal inheritance of acquired metabolic traits

BACKGROUND

The concept of the inheritance of acquired traits, a foundational principle of Lamarck's evolutionary theory, has garnered renewed attention in recent years. Evidence for this phenomenon remained limited for decades but gained prominence with the Överkalix cohort study in 2002. This study revealed a link between cardiovascular disease incidence and the food availability experienced by individuals' grandparents during their slow growth periods, reigniting interest in the inheritance of acquired traits, particularly in the context of non-communicable diseases. This scientometric analysis and systematic review comprehensively explores the current landscape of paternally transmitted acquired metabolic traits.

RESULTS

Utilizing Scopus Advanced search and meticulous screening, we included mammalian studies that document the inheritance or modification of metabolic traits in subsequent generations of unexposed descendants. Our inclusive criteria encompass intergenerational and transgenerational studies, as well as multigenerational exposures. Predominantly, this field has been driven by a select group of researchers, potentially shaping the design and focus of existing studies. Consequently, the literature primarily comprises transgenerational rodent investigations into the effects of ancestral exposure to environmental pollutants on sperm DNA methylation. The complexity and volume of data often lead to multiple or redundant publications. This practice, while understandable, may obscure the true extent of the impact of ancestral exposures on the health of non-exposed descendants. In addition to DNA methylation, studies have illuminated the role of sperm RNAs and histone marks in paternally acquired metabolic disorders, expanding our understanding of the mechanisms underlying epigenetic inheritance.

CONCLUSIONS

This review serves as a comprehensive resource, shedding light on the current state of research in this critical area of science, and underscores the need for continued exploration to uncover the full spectrum of paternally mediated metabolic inheritance.

Paternal programming of fetoplacental and offspring metabolic disorders

The alarming increase in the prevalence of metabolic pathologies is of worldwide concern and has been linked not only to genetic factors but also to a large number of non-genetic factors. In recent years, there has been increasing interest in the study of the programming of metabolic diseases, such as type 2 diabetes mellitus (T2DM) and obesity, by paternal exposure, a paradigm termed "Paternal Origins of Health and Disease" (POHaD). This term derives from the better known "Developmental Origins of Health and Disease" (DOHaD), which focuses on the involvement of the maternal intrauterine environment and complications during pregnancy associated with the health and disease of the offspring. Studies on paternal programming have documented environmentally induced epigenetic modifications in the male germline and in seminal plasma, which lead to intergenerational and transgenerational phenotypes, evident already during fetoplacental development. Studies with animal models at both ends of the nutritional spectrum (undernutrition or overnutrition) have been performed to understand the possible mechanisms and signaling pathways leading to the programming of metabolic disorders by exploring epigenetic changes throughout the life of the offspring. The aim of this review was to address the evidence of the programming of fetoplacental developmental alterations and metabolic pathologies in the offspring of males with metabolic disorders and unhealthy exposures, highlighting the mechanisms involved in such programming and looking for paternal interventions to reduce negative health outcomes in the offspring.

Effects of paternal high-fat diet and maternal rearing environment on the gut microbiota and behavior

Exposing a male rat to an obesogenic high-fat diet (HFD) influences attractiveness to potential female mates, the subsequent interaction of female mates with infant offspring, and the development of stress-related behavioral and neural responses in offspring. To examine the stomach and fecal microbiome's potential roles, fecal samples from 44 offspring and stomach samples from offspring and their fathers were collected and bacterial community composition was studied by 16 small subunit ribosomal RNA (16S rRNA) gene sequencing. Paternal diet (control, high-fat), maternal housing conditions (standard or semi-naturalistic housing), and maternal care (quality of nursing and other maternal behaviors) affected the within-subjects alpha-diversity of the offspring stomach and fecal microbiomes. We provide evidence from beta-diversity analyses that paternal diet and maternal behavior induced community-wide shifts to the adult offspring gut microbiome. Additionally, we show that paternal HFD significantly altered the adult offspring Firmicutes to Bacteroidetes ratio, an indicator of obesogenic potential in the gut microbiome. Additional machine-learning analyses indicated that microbial species driving these differences converged on Bifidobacterium pseudolongum. These results suggest that differences in early-life care induced by paternal diet and maternal care significantly influence the microbiota composition of offspring through the microbiota-gut-brain axis, having implications for adult stress reactivity.

Effect of Paternal Diet on Spermatogenesis and Offspring Health: Focus on Epigenetics and Interventions with Food Bioactive Compounds

Infertility is a growing public health problem. Consumption of antioxidant bioactive food compounds (BFCs) that include micronutrients and non-nutrients has been highlighted as a potential strategy to protect against oxidative and inflammatory damage in the male reproductive system induced by obesity, alcohol, and toxicants and, thus, improve spermatogenesis and the fertility parameters. Paternal consumption of such dietary compounds could not only benefit the fathers but their offspring as well. Studies in the new field of paternal origins of health and disease show that paternal malnutrition can alter sperm epigenome, and this can alter fetal development and program an increased risk of metabolic diseases and breast cancer in adulthood. BFCs, such as ascorbic acid, α-tocopherol, polyunsaturated fatty acids, trace elements, carnitines, N-acetylcysteine, and coenzyme Q10, have been shown to improve male gametogenesis, modulate epigenetics of germ cells, and the epigenetic signature of the offspring, restoring offspring metabolic health induced by stressors during early life. This indicates that, from a father’s perspective, preconception is a valuable window of opportunity to start potential nutritional interventions with these BFCs to maximize sperm epigenetic integrity and promote adequate fetal growth and development, thus preventing chronic disease in adulthood.

Effects of paternal overnutrition and interventions on future generations

In the last two decades, evidence from human and animal studies suggests that paternal obesity around the time of conception can have adverse effects on offspring health through developmental programming. This may make significant contributions to the current epidemic of obesity and related metabolic and reproductive complications like diabetes, cardiovascular disease, and subfertility/infertility. To date, changes in seminal fluid composition, sperm DNA methylation, histone composition, small non-coding RNAs, and sperm DNA damage have been proposed as potential underpinning mechanism to program offspring health. In this review, we discuss current human and rodent evidence on the impact of paternal obesity/overnutrition on offspring health, followed by the proposed mechanisms, with a focus on sperm DNA damage underpinning paternal programming. We also summarize the different intervention strategies implemented to minimize effects of paternal obesity. Upon critical review of literature, we find that obesity-induced altered sperm quality in father is linked with compromised offspring health. Paternal exercise intervention before conception has been shown to improve metabolic health. Further work to explore the mechanisms underlying benefits of paternal exercise on offspring are warranted. Conversion to healthy diets and micronutrient supplementation during pre-conception have shown some positive impacts towards minimizing the impact of paternal obesity on offspring. Pharmacological approaches e.g., metformin are also being applied. Thus, interventions in the obese father may ameliorate the potential detrimental impacts of paternal obesity on offspring.

Paternal high protein diet modulates body composition, insulin sensitivity, epigenetics, and gut microbiota intergenerationally in rats

Mounting evidence demonstrates that paternal diet programs offspring metabolism. However, the contribution of a pre-conception paternal high protein (HP) diet to offspring metabolism, gut microbiota, and epigenetic changes remains unclear. Here we show that paternal HP intake in Sprague Dawley rats programs protective metabolic outcomes in offspring. Compared to paternal high fat/sucrose (HF/S), HP diet improved body composition and insulin sensitivity and improved circulating satiety hormones and cecal short-chain fatty acids compared to HF/S and control diet (P < .05). Further, using 16S rRNA gene sequencing to assess gut microbial composition, we observed increased alpha diversity, distinct bacterial clustering, and increased abundance of Bifidobacterium, Akkermansia, Bacteroides, and Marvinbryantia in HP fathers and/or male and female adult offspring. At the epigenetic level, DNMT1and 3b expression was altered intergenerationally. Our study identifies paternal HP diet as a modulator of gut microbial composition, epigenetic markers, and metabolic function intergenerationally.

Epigenetics in NAFLD/NASH: Targets and therapy

Recently non-alcoholic fatty liver disease (NAFLD) has grabbed considerable scientific attention, owing to its rapid increase in prevalence worldwide and growing burden on end-stage liver diseases. Metabolic syndrome including obesity, diabetes, and hypertension poses a grave risk to NAFLD etiology and progression. With no drugs available, the mainstay of NAFLD management remains lifestyle changes with exercise and dietary modifications. Nonselective drugs such as metformin, thiazolidinediones (TZDs), ursodeoxycholic acid (UDCA), silymarin, etc., are also being used to target the interrelated pathways for treating NAFLD. Considering the enormous disease burden and the unmet need for drugs, fresh insights into pathogenesis and drug discovery are required. The emergence of the field of epigenetics offers a convincing explanation for the basis of lifestyle, environmental, and other risk factors to influence NAFLD pathogenesis. Therefore, understanding these epigenetic modifications to target the primary cause of the disease might prove a rational strategy to prevent the disease and develop novel therapeutic interventions. Apart from describing the role of epigenetics in the pathogenesis of NAFLD as in other reviews, this review additionally provides an elaborate discussion on exploiting the high plasticity of epigenetic modifications in response to environmental cues, for developing novel therapeutics for NAFLD. Besides, this extensive review provides evidence for epigenetic mechanisms utilized by several potential drugs for NAFLD.