Gut feelings 1. Mind, mood and gut in irritable bowel syndrome: approaches to psychiatric care

Association between Gut Microbiota and Infant's Temperament in the First Year of Life in a Chinese Birth Cohort

Infant temperament characteristics play a critical role in children's developmental pathways and can predict adulthood psychopathology. The diversity and composition of the gut microbiota are associated with human temperament in both adults and young children. However, the relationship between the gut microbiota and temperament in 12-month-old infants is rarely studied; this developmental period is when temperament reaches a relatively stable stage. We used high-throughput sequencing methods to explore whether temperament characteristics were associated with gut microbiota diversity and composition. Infants' fecal samples were collected at 12 months of age for the gut microbiota analysis. Based on the primary caregivers' reports, infants' temperaments were measured using the Infant Behavior Questionnaire-revised (IBQ-R). This study included 51 infants, including 20 boys and 31 girls, with a mean age of 12.25 months. Results showed that soothability was positively correlated with maternal education level (β = 0.29, p = 0.043, adjust p = 0.025) and the abundance of Bifidobacterium genera (β = 0.62, p = 0.004, adjust p = 0.002). Conversely, cuddliness was negatively correlated with the abundance of Hungatella genera. There was no significant difference in temperament based on gender. This study demonstrated that gut microbiota composition was associated with temperament in 12-month-old infants. These results point to the importance of gut microbiota balance. Future studies on the mechanisms behind the gut microbiota affecting temperament are warranted.

Role of stem cell growth factor/c-Kit in the pathogenesis of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional bowel disease with a complicated etiopathogenesis, often characterized by gastrointestinal motility disorder and high visceral sensitivity. IBS is a comprehensive multi-systemic disorder, with the interaction of multiple factors, such as mental stress, intestinal function and flora, heredity, resulting in the disease. The existence of a common mechanism underlying the aforementioned factors is currently unknown. The lack of therapies that comprehensively address the disease symptoms, including abdominal pain and diarrhea, is a limitation of current IBS management. The current review has explored the role of the SCF/c-Kit receptor/ligand system in IBS. The SCF/c-Kit system constitutes a classical ligand/receptor tyrosine kinase signaling system that mediates inflammation and smooth muscle contraction. Additionally, it provides trophic support to neural crest-derived cell types, including the enteric nervous system and mast cells. The regulation of SCF/c-Kit on the interstitial cells of Cajal (ICC) suggest that it may play a key role in the aberrant intestinal dynamics and high visceral sensitivity observed in IBS. The role of the SCF/c-Kit system in intestinal motility, inflammation and nerve growth has been reported. From the available biomedical evidence on the pathogenesis of IBS, it has been concluded that the SCF-c-Kit system is a potential therapeutic target for rational drug design in the treatment of IBS.

Dietary 2'-Fucosyllactose Enhances Operant Conditioning and Long-Term Potentiation via Gut-Brain Communication through the Vagus Nerve in Rodents

2´-fucosyllactose (2´-FL) is an abundant human milk oligosaccharide (HMO) in human milk with diverse biological effects. We recently reported ingested 2´-FL stimulates central nervous system (CNS) function, such as hippocampal long term potentiation (LTP) and learning and memory in rats. Conceivably the effect of 2´-FL on CNS function may be via the gut-brain axis (GBA), specifically the vagus nerve, and L-fucose (Fuc) may play a role. This study had two aims: (1) determine if the effect of ingested 2´-FL on the modulation of CNS function is dependent on the integrity of the molecule; and (2) confirm if oral 2´-FL modified hippocampal LTP and associative learning related skills in rats submitted to bilateral subdiaphragmatic vagotomy. Results showed that 2´-FL but not Fuc enhanced LTP, and vagotomy inhibited the effects of oral 2´-FL on LTP and associative learning related paradigms. Taken together, the data show that dietary 2´-FL but not its Fuc moiety affects cognitive domains and improves learning and memory in rats. This effect is dependent on vagus nerve integrity, suggesting GBA plays a role in 2´-FL-mediated cognitive benefits.