16 research outputs found
A prospective, randomized, double-blind, placebo-controlled parallel-group dual site trial to evaluate the effects of a Bacillus coagulans-based product on functional intestinal gas symptoms
Young Aphids Avoid Erroneous Dropping when Evading Mammalian Herbivores by Combining Input from Two Sensory Modalities
Mammalian herbivores may incidentally ingest plant-dwelling insects while foraging. Adult pea aphids (Acyrthosiphon pisum) avoid this danger by dropping off their host plant after sensing the herbivore's warm and humid breath and the vibrations it causes while feeding. Aphid nymphs may also drop (to escape insect enemies), but because of their slow movement, have a lower chance of finding a new plant. We compared dropping rates of first-instar nymphs with those of adults, after exposing pea aphids to different combinations of simulated mammalian breath and vibrations. We hypothesized that nymphs would compensate for the greater risk they face on the ground by interpreting more conservatively the mammalian herbivore cues they perceive. Most adults dropped in response to breath alone, but nymphs rarely did so. Breath stimulus accompanied by one concurrent vibrational stimulus, caused a minor rise in adult dropping rates. Adding a second vibration during breath had no additional effect on adults. The nymphs, however, relied on a combination of the two types of stimuli, with a threefold increase in dropping rates when the breath was accompanied by one vibration, and a further doubling of dropping rates when the second vibration was added. The age-specificity of the aphids' herbivore detection mechanism is probably an adaptation to the different cost of dropping for the different age groups. Relying on a combination of stimuli from two sensory modalities enables the vulnerable nymphs to avoid costly mistakes. Our findings emphasize the importance of the direct trophic effect of mammalian herbivory for plant-dwelling insects
Efficacy and Side Effect Profile of Different Formulations of Metformin: A Systematic Review and Meta-Analysis
Microbiota in health and irritable bowel syndrome: current knowledge, perspectives and therapeutic options
Abstract The gastrointestinal tract is a natural reservoir of microbiota. The gut is germ-free at birth, but rapidly becomes host to various bacteria establishing a progressively mutual relationship. The composition of gut microbiota is individual-specific and depends on the genotype of the host and environmental factors. Novel techniques have been used to characterize gastrointestinal microbiota, including genomic approaches. The bacterial profile shows that dominant and minor phyla are present in the gastrointestinal tract. From the proximal to the distal segments of the gut the bacterial density gradually increases, reaching an estimated 10(11) to 10(12) bacteria per gram of colonic content. Dynamic interactions between gut and microbiota play a physiological role in metabolic, protective and structural functions, while dysbiosis contributes to several diseases. Microbiota appear to play a role in IBS, where qualitative and quantitative changes of bacteriaoccur in IBS subtypes. Initial therapeutic approaches in IBS have focused on microbiota. The relationship between perturbations of the microbiota, mucosal inflammation and IBS remains to be further investigated.The gastrointestinal tract is a natural reservoir of microbiota. The gut is germ-free at birth, but rapidly becomes host to various bacteria establishing a progressively mutual relationship. The composition of gut microbiota is individual-specific and depends on the genotype of the host and environmental factors. Novel techniques have been used to characterize gastrointestinal microbiota, including genomic approaches. The bacterial profile shows that dominant and minor phyla are present in the gastrointestinal tract. From the proximal to the distal segments of the gut the bacterial density gradually increases, reaching an estimated 10(11) to 10(12) bacteria per gram of colonic content. Dynamic interactions between gut and microbiota play a physiological role in metabolic, protective and structural functions, while dysbiosis contributes to several diseases. Microbiota appear to play a role in IBS, where qualitative and quantitative changes of bacteriaoccur in IBS subtypes. Initial therapeutic approaches in IBS have focused on microbiota. The relationship between perturbations of the microbiota, mucosal inflammation and IBS remains to be further investigated