Intestines

The growth-inhibitory activity of materials derived from the fruit of Terminalia chebula was evaluated against six intestinal bacteria by means of an impregnated paper disk agar diffusion method. The butanol fraction of T. chebula extract had profound growth-inhibitory activity at a concentration of 5 mg per disk. The biologically active component isolated from the T. chebula fruits was identified with a variety of spectroscopic analyses as ethanedioic acid. The growth responses varied in accordance with the bacterial strain, chemical, and dosage tested.

A study was conducted to evaluate some plant parts (already tested for their antimethanogenic activity in in vitro gas production test in the authors' laboratory) as feed additive to combat methane emission from sheep. Sixteen male sheep with average body weight of 29.96±1.69 kg (22 months of age) were divided into four groups in a randomized block design. The animals were fed on a diet containing forage to concentrate ratio of 1:1. The concentrate fraction composed (in parts) of maize grain, 32; wheat bran, 45; deoiled soybean meal, 20; mineral mixture, 2 and common salt, 1.

C57BL/6J mice carrying the Min allele of Adenomatous polyposis coli (Apc) develop numerous adenomas along the entire length of the intestine and consequently die at an early age. This short lifespan would prevent the accumulation of somatic genetic mutations or epigenetic alterations necessary for tumor progression. To overcome this limitation, we generated F(1) Apc(Min/+) hybrids by crossing C57BR/cdcJ and SWR/J females to C57BL/6J Apc(Min/+) males. These hybrids developed few intestinal tumors and often lived longer than 1 year.

Multicellular organisms are composed of an interactive network of various tissues that are functionally organized as discrete organs. If aging were slowed in a specific tissue or organ how would that impact longevity at the organismal level? In recent years, molecular genetic approaches in invertebrate model systems have dramatically improved our understanding of the aging process and have provided insight into the preceding question.

Both poikilotherms and homeotherms live longer at lower body temperatures, highlighting a general role of temperature reduction in lifespan extension. However, the underlying mechanisms remain unclear. One prominent model is that cold temperatures reduce the rate of chemical reactions, thereby slowing the rate of aging. This view suggests that cold-dependent lifespan extension is simply a passive thermodynamic process. Here, we challenge this view in C. elegans by showing that genetic programs actively promote longevity at cold temperatures.

The nematode Caenorhabditis elegans has in recent years been proven to be a powerful in vivo model for testing antimicrobial compounds. We report here that the alkaloid compound Harmane (2-methyl-?-carboline) increases the lifespan of nematodes infected with a human pathogen, the Shiga toxin-producing Escherichia coli O157:H7 strain EDL933 and several other bacterial pathogens. This was shown to be unrelated to the weak antibiotic effect of Harmane. Using GFP-expressing E. coli EDL933, we showed that Harmane does not lower the colonization burden in the nematodes.

Multicellular organisms are composed of an interactive network of various tissues that are functionally organized as discrete organs. If aging were slowed in a specific tissue or organ how would that impact longevity at the organismal level? In recent years, molecular genetic approaches in invertebrate model systems have dramatically improved our understanding of the aging process and have provided insight into the preceding question.

BACKGROUND: Zinc deficiency due to poor nutrition or genetic mutations in zinc transporters is a global health problem and approaches to providing effective dietary zinc supplementation while avoiding potential toxic side effects are needed. METHODS/PRINCIPAL FINDINGS: Conditional knockout of the intestinal zinc transporter Zip4 (Slc39a4) in mice creates a model of the lethal human genetic disease acrodermatitis enteropathica (AE).

Gut microbiota is found in virtually any metazoan, from invertebrates to vertebrates. It has long been believed that gut microbiota, more specifically, the activity of the microbiome and its metabolic products, directly influence a variety of aspects in metazoan physiology. However, the exact molecular relationship among microbe-derived gut metabolites, host signaling pathways, and host physiology remains to be elucidated. Here we review recent discoveries regarding the molecular links between gut metabolites and host physiology in different invertebrate and vertebrate animal models.

The incidence of intestinal nutrient malabsorption increases with age. Therefore, an important question is whether there are age-related changes in intestinal nutrient absorption which may contribute to a decline in absorptive capacity. Sugar and amino acid transport per mg intestine generally decreases with age. The proximate mechanism underlying this age-related decrease in transport activity is a decrease in number of transporters per mg.