University of Macau / Institute of Chinese Medical Sciences

published_or_final_version / Pharmacology / Master / Master of Philosophy

published_or_final_version / Pharmacology / Doctoral / Doctor of Philosophy

A dextran sulphate (DS) model of ulcerative colitis was used to examine the effects of macronutrient restriction with (MR+PRO) and without (MR) probiotic supplementation (VSL#3RTM) on protein metabolism and growth. MR and MR+PRO decreased weight and chest circumference gain, but had no effect on linear growth of piglets. MR decreased the protein fractional synthesis rate (FSR) of liver, masseter, longissimus dorsi, colon, as well as plasma albumin, measured by stable isotope tracer L-[ring-2H 5]phenylalanine. MR+PRO increased the FSR of hepatic proteins by greater than 70% and increased both the FSR and absolute synthesis rate (ASR) of the total plasma protein pool, albumin and fibrinogen. Over 11 days, MR+PRO piglets showed a smaller decrease in plasma total protein concentrations than WN piglets, and maintained higher albumin levels than either WN or MR piglets. These findings highlight the importance of adequate nutrition during gastrointestinal inflammation and show that when food intake is decreased, probiotics stimulate liver protein synthesis and increase the acute phase protein response, similar to the well-nourished state.

Access to abstract permanently restricted to Ball State community only. / Access to thesis permanently restricted to Ball State community only. / Department of Physiology and Health Science

No description available.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Bifidobacterium infantis (BI) and other probiotics are non-pathogenic living organisms that have recently gained attention for their possible therapeutic implications on the health of the digestive tract. The mechanisms by which probiotics exert their effects are largely unknown. This study explored the protective and regulatory effect of oral BI on the enteric nervous system (ENS) in the TNBS-induced colitis rats. Electrical field stimulation and chemical stimulation by serotonin (5-HT) were used to elicit changes in the short-circuit current (Isc) response of the colonic rat tissue. BI-fed colitis rats expressed trends of higher secretomotor activity and revealed signs of decreased macroscopic inflammatory damage when compared to sham-fed colitis rats, suggesting a protective and preventative role of oral BI. These findings may provide additional insights for understanding the prophylactic and therapeutic value of specific probiotics in intestinal inflammatory disorders, offering the possibility of a noninvasive alternative to toxic and immune-compromising drugs. / Access to thesis permanently restricted to Ball State community only / Department of Physiology and Health Science

Dynamic molecular interactions between the microbiota and the intestinal mucosa play an important role in the establishment and maintenance of mucosal homeostasis. Aberrant host- microbiota interaction could lead to many diseases such as inflammatory bowel disease. The aim of our study was to evaluate the commensal and probiotic bacteria activities and their ability to induce pathological or exert beneficial effects. The most important trigger for immune system development is an exposure to microbial components. Here, we show that there is a time window at about three weeks of age, which enables the artificial colonization of germ free mice by a single oral dose of cecal content. The delayed colonization by either inoculation or co-housing causes permanent changes in immune system reactivity, which may downgrade the results of experiments performed on first generation of colonized animals. In this thesis we report that even non-living commensal bacteria such as Parabacteroides distasonis (mPd) or well known probiotics such as L. casei DN-114 001 (Lc) possess anti-inflammatory effects in experimental model of colitis. The mechanisms that this effect is achieved by the lysate of L. casei DN-114 001 comprise: a) improvement in the gut barrier function, b) correction of the dysbiosis, and c) modulation of the...