• Food Science of Animal Resources
• /
• v.43 no.4
• /
• pp.612-624
• /
• 2023

The gut-brain axis encompasses a bidirectional communication pathway between the gastrointestinal microbiota and the central nervous system. There is some evidence to suggest that probiotics may have a positive effect on cognitive function, but more research is needed before any definitive conclusions can be drawn. Inflammation-induced by lipopolysaccharide (LPS) may affect cognitive function. To confirm the effect of probiotics on oxidative stress induced by LPS, the relative expression of antioxidant factors was confirmed, and it was revealed that the administration of probiotics had a positive effect on the expression of antioxidant-related factors. After oral administration of probiotics to mice, an intentional inflammatory response was induced through LPS i.p., and the effect on cognition was confirmed by the Morris water maze test, nitric oxide (NO) assay, and interleukin (IL)-1β enzyme-linked immunosorbent assay performed. Experimental results, levels of NO and IL-1β in the blood of LPS i.p. mice were significantly decreased, and cognitive evaluation using the Morris water maze test showed significant values in the latency and target quadrant percentages in the group that received probiotics. This proves that intake of these probiotics improves cognitive impairment and memory loss through anti-inflammatory and antioxidant mechanisms.

• BMB Reports
• /
• v.56 no.1
• /
• pp.15-23
• /
• 2023

After birth, animals are colonized by a diverse community of microorganisms. The digestive tract is known to contain the largest number of microbiome in the body. With emergence of the gut-brain axis, the importance of gut microbiome and its metabolites in host health has been extensively studied in recent years. The establishment of organoid culture systems has contributed to studying intestinal pathophysiology by replacing current limited models. Owing to their architectural and functional complexity similar to a real organ, co-culture of intestinal organoids with gut microbiome can provide mechanistic insights into the detrimental role of pathobiont and the homeostatic function of commensal symbiont. Here organoid-based bacterial co-culture techniques for modeling host-microbe interactions are reviewed. This review also summarizes representative studies that explore impact of enteric microorganisms on intestinal organoids to provide a better understanding of host-microbe interaction in the context of homeostasis and disease.

• BMB Reports
• /
• v.57 no.3
• /
• pp.149-154
• /
• 2024

The stomach has emerged as a crucial endocrine organ in the regulation of feeding since the discovery of ghrelin. Gut-derived hormones, such as ghrelin and cholecystokinin, can act through the vagus nerve. We previously reported the satiety effect of hypothalamic clusterin, but the impact of peripheral clusterin remains unknown. In this study, we administered clusterin intraperitoneally to mice and observed its ability to suppress fasting-driven food intake. Interestingly, we found its synergism with cholecystokinin and antagonism with ghrelin. These effects were accompanied by increased c-fos immunoreactivity in nucleus tractus solitarius, area postrema, and hypothalamic paraventricular nucleus. Notably, truncal vagotomy abolished this response. The stomach expressed clusterin at high levels among the organs, and gastric clusterin was detected in specific enteroendocrine cells and the submucosal plexus. Gastric clusterin expression decreased after fasting but recovered after 2 hours of refeeding. Furthermore, we confirmed that stomachspecific overexpression of clusterin reduced food intake after overnight fasting. These results suggest that gastric clusterin may function as a gut-derived peptide involved in the regulation of feeding through the gut-brain axis.

• Development and Reproduction
• /
• v.13 no.4
• /
• pp.207-215
• /
• 2009

Numerous factors can affect the activities of hypothalamus-pituitary-gonad (HPG) hormonal axis, resulting in alteration of reproductive capacity or status such as onset of puberty and menopause. Soon after the finding of leptin, a multifunctional hormone secreted from adipocytes, a close relationship between reproduction and body energy balance have been manifested. Ghrelin, another multifunctional hormone from gastrointestinal tract, is an endogenous ligand of growth hormone secretagogue receptor (GHSR), and is thought to be a counterpart of leptin in the regulation of energy homeostasis. As expected, ghrelin can also modulate the reproductive capacity through the modulation of activities of HPG axis. This paper summarizes the current knowledge on the discovery, gene structures, tissue distribution and roles of ghrelin and GHSRs in mammalian reproduction in particular modulation of reproductive hormone secretion in HPG axis. Like POMC gene expression in pituitary gland, preproghrelin gene can generate a complex repertoire of transcripts which further undergo alternative splicing and posttranslational modifications. Concerning the roles of preproghrelin gene products in the control of body physiology except energy homeostasis, limited knowledge is available so far. Several lines of evidence, however, show the interplay of ghrelin between metabolism and reproduction. In rat and human, the distribution of ghrelin receptor GHSRs (GHSR1a and GHSR1b) has been confirmed not only in the hypothalamus and pituitary which were originally postulated as target of ghrelin but also in the testis and ovary. Expression of the preproghrelin gene in the brain and gonads was also verified, suggesting the local role (s) of ghrelin in HPG axis. Ghrelin might play a negative modulator in the secretions of hypothalamic GnRH, pituitary gonadotropins and gonadal steroids though the action on pituitary is still questionable. Recent studies suggest the involvement of ghrelin in regulation of puberty onset and possibly of menopause entry. It is now evident that ghrelin is a crucial hormomal component in 'brain-gut' axis, and is a strong candidate links between metabolism and reproduction. Opposite to that for leptin, ghrelin signaling is likely representing the 'hunger' state of body energy balance and is necessary to avoid the energy investment into reproduction which has not a top priority in maintaining homeostasis. Further researches are needed to gain a deep insight into the more precise action mechanism and role of ghrelin in reproduction, and to guarantee the successful biomedical applications.

• Journal of Dairy Science and Biotechnology
• /
• v.39 no.3
• /
• pp.94-103
• /
• 2021

The lack of an effective treatment for Alzheimer's disease (AD) stems primarily from incomplete understanding of AD's causes. A rapidly growing number of scientific reports highlight important roles played by peripheral infections and intestinal bacterial flora in pathological and physiological functions involving the microbiome-intestine-brain axis. The microbiome controls basic aspects of the central nervous system (CNS), immunity, and behavior, in health and disease. Changes in the density and composition of the microbiome have been linked to disorders of the immune, endocrine, and nervous systems, including mood changes, depression, increased susceptibility to stressors, and autistic behaviors. There is no doubt that in patients with AD, restoration of the intestinal microbiome to a composition reminiscent of that found in healthy adult humans will significantly slow the progression of neurodegeneration, by ameliorating inflammatory reactions and/or amyloidogenesis. In the near future, better understanding of bidirectional communication between the brain and microbiota will allow the development of functional diets using specific probiotic bacteria.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.23 no.6
• /
• pp.567-576
• /
• 2020

Purpose: Not enough attention has been paid to defecation habits in Japan. This study aimed to emphasize the importance of defecation habits on health and function in Japanese pupils. Methods: Using multiple regression analysis, 2,722 questionnaires obtained from pupils in grades 5 to 12 were analyzed to determine lifestyle habits associated with defecation frequency. Results: Significant regression formulae for defecation scores were obtained for all school types: elementary school (ES) (adjusted R²=0.08, p<0.001), junior high school (JHS) (0.09, p<0.001), and senior high school (SHS) (0.15, p<0.001). The following factors were associated with poorer defecation scores, according to school type: female gender (all 3 school types), breakfast skipping (elementary and JHSs), lower physical activity (JHSs and SHSs), and longer school-day screen time (elementary and SHSs). In addition, poorer self-reported academic performance scores in ES, less standardized body mass index (BMI) in JHS, and shorter non-school- day screen time scores in SHS, were associated with poorer defecation scores. Conclusion: Poor defecation frequency showed significant associations with various lifestyle habits, such as breakfast skipping, physical activity, and screen time, among pupils. Academic performance and standardized BMI were also associated with defecation frequency. More attention should be paid to defecation frequency to sustain health and function in pupils.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.5
• /
• pp.630-638
• /
• 2017

Metabolic syndrome is associated with risk of developing cardiovascular disease and type 2 diabetes, and incidence of metabolic syndrome is showing an increasing trend. Recently, coffee intake is argued to have an effect on the gut-brain axis, and it is widely recognized has being associated with many beneficial effects, including those related to metabolic imbalance. However, it is essential to understand how the dietary aspects of coffee intake and type of coffee intake affect diet and overall health. The association between coffee consumption and health is still controversial, and the average body weight of the Korean population is increasing. Therefore, this study focused on analyzing the effects of instant coffee (particularly instant coffee mix) in Korea, especially with respect to metabolic syndrome. The study was conducted on participating subject's that visited Sun-Han hospital, and instant coffee mix intakes and metabolic risk factors during the study period were examined from July 2015 to June 2016. The results showed that waist circumference (r=0.405, P=0.036) and serum triglyceride level (r=0.435, P=0.023) were positively correlated with instant coffee mix intakes. In addition, instant coffee mix intakes were significantly associated with serum triglyceride level in subjects who consumed more than 1 cup/d of coffee (P<0.05). Therefore, subjects should be careful about fat intake and be educated about the type and frequency of coffee intakes.