Heng-Wei Cheng

By Heng-wei Cheng

Part of the book: Inflammatory Diseases

By Heng-Wei Cheng, Sha Jiang and Jiaying Hu

Intestinal bacteria release various neuroactive compounds directly or indirectly regulating brain function to modulate host health and behavior through the gut-brain axis. Probiotics have been used as dietary supplements to target gut microbiota (microbiome) for prevention or therapeutic treatment of various diseases including mental disorders. In our study, chickens were used as an animal model to assess, if dietary supplementation of probiotic, Bacillus subtilis, reduces aggressive behaviors following social challenge. Chickens of an aggressive line were housed in single-hen cages. At 24 weeks of age, the hens were paired with similar body weight to identify the dominance rank (day 0). The subordinate and dominant of each pair were fed a regular layer diet or the diet mixed with 250 ppm probiotics for 2 weeks, then the second behavior test was performed between the same pair (day 14). The display of aggressive behaviors in the regular diet-fed chickens was not affected between the levels at day 0 and day 14, while the frequency of threat and aggressive pecking were reduced in the probiotic-fed chickens compared to the levels at day 0. These results suggest dietary probiotic, Bacillus subtilis, could be a suitable strategy for increasing hosts’ mental health.

Part of the book: Oral Health by Using Probiotic Products

By Xiaohong Huang, Xiaohua Li and Heng-Wei Cheng

Neuropsychiatry underlies personality development and social functioning. Borderline personality disorder exhibits high trait aggression and is associated with tryptophan hydroxylase polymorphisms. The acute tryptophan depletion reduces plasma and cerebrospinal fluid tryptophan availability and brain serotonin concentrations, leading to alterations in personality and trait-related behaviors. Tryptophan is essential for fatal neurodevelopment and immunomodulation in pregnancy. Gestational tryptophan fluctuation induced by maternal metabolic disorders or drug administrations may account for the maternal-fetal transmission determining neurogenesis and microbial development, consequentially shaping the long-standing patterns of thinking and behavior. However, it is not possible to assess the gestational tryptophan exposure effects on fetal brain and gastrointestinal system in humans for ethical reasons. The maternal–fetal microbe transmission in rodents during gestation, vaginal delivery, and breastfeeding is inevitable. Chicken embryo may be an alternative and evidence from the chicken embryo model reveals that gestational tryptophan fluctuation, i.e., exposed to excessive tryptophan or its metabolite, serotonin, attenuates aggressiveness and affects peer sociometric status. This chapter discusses the gestational tryptophan fluctuation as a risk factor of personality disorders in offspring and the prevention of personality disorders by dietary tryptophan control and medication therapy management during pregnancy.

Part of the book: Cognitive Behavioral Therapy