Metformin Alters the Chemotaxis and Flagellar Motility of Escherichia coli

Metformin is a biguanide molecule that is widely prescribed to treat type 2 diabetes and metabolic syndrome. Although it is known that metformin promotes the lifespan by altering intestinal microorganism metabolism, how metformin influences and alters the physiological behavior of microorganisms remains unclear. Here we studied the effect of metformin on the behavior alterations of the model organism Escherichia coli (E. coli), including changes in chemotaxis and flagellar motility that plays an important role in bacterial life. It was found that metformin was sensed as a repellent to E. coli by tsr chemoreceptors. Moreover, we investigated the chemotactic response of E. coli cultured with metformin to two typical attractants, glucose and α-methyl-DL-aspartate (MeAsp), finding that metformin prolonged the chemotactic recovery time to the attractants, followed by the recovery time increasing with the concentration of stimulus. Metformin also inhibited the flagellar motility of E. coli including the flagellar motor rotation and cell swimming. The inhibition was due to the reduction of torque generated by the flagellar motor. Our discovery that metformin alters the behavior of chemotaxis and flagellar motility of E. coli could provide potential implications for the effect of metformin on other microorganisms.

Reconstruction of intestinal microecology of Type 2 diabetes by Fecal Microbiota Transplantation: Why and How

Type 2 diabetes (T2D) is a chronic metabolic disease characterized by hyperglycemia due to insulin resistant. Mounting evidence has correlated T2D to alterations in the composition of gut microbiota. Accordingly, targeting the gut microbiota has become an emerging strategy to benefit the T2D management. To get a better insight into the rationale for targeting gut microbiota in T2D treatment, we herein reviewed the change of gut microbiota composition in T2D, factors shaping gut microbiota, and potential mechanisms about contribution of gut microbiota to T2D pathogenesis.At present, it has become possible to use intestinal microorganism capsules, bacteria liquid and other preparations to carry out FMT for the treatment and intervention of T2D with insulin resistance and immune-mediated Type 1 diabetes(T1D).

​Insect Plant Interaction with Reference to Secondary Metabolites: A Review

Plant and herbivorous insect share a contradictory but everlasting relationship. To cope with the herbivores, plant invested its energy in the production of various defensive chemicals which are known as plant secondary metabolites (PSMs). During coevolution with plants, insects also adapted themselves to counter plant defensive mechanisms. The secreted saliva and ovipositional fluids of insects induce the production of secondary metabolites in plants. Plants also produce compounds constitutively in the tissues that are susceptible to insect attack. These compounds reduce insect growth and development of insects through interfering with the developmental phases, acting as feeding deterrent, reducing nutritive value, affecting protein digestion and the production of substances toxic to them. On the contrary, insect’s adaptations to PSMs include the detoxification of plant toxins, conversion of the toxic compounds into conducible form for its growth and development, development of feeding choice based on the concentration of PSMs, quicker absorption and elimination as feces and obtaining the help of symbiotic intestinal microorganism to inactivate toxic materials. Furthermore, insects also utilize PSMs as chemical cues mediated through their chemoreceptive systems. The selection of host plants by monophagous insect is sometimes concentrated on the production of particular PSMs. Secondary metabolites also act as attractant to insect pollinators by exhibiting distinctive odors. Insects also store toxic PSMs which are used by them against their predators and in giving protection to eggs. However, this intrinsic capability of plants to produce defensive chemicals in response to insect attack should be explored to a wide extent to optimize the performance of PSMs.

The differences of intestinal development and microorganism between male and female ducks

Background There are great differences in physiological and biological functions between animals of different genders. However, whether there would be a consensus in duck intestinal development and microorganisms is still unknown. Methods Male and female ducks were weighed at 2, 5 and 10 weeks, respectively, then the duodenum, jejunum, ileum and cecum were sampled and measured, and the content were analyzed by 16S RNA. Results The results showed that male duck hold shorter intestinal length with higher density and jejunum VH/CD, and the similarity, evenness and diversity of the total intestinal microorganism of male duck were higher, with 99.66% OTUs shared by both gender, while Rikenellae , Prevotella and Nocardia were only in male duck. Proeobacteria hold higher abundance than Bacteroidetes in female intestine, while the value of Firmicutes/Bacteroides was lower than male duck. Whats more, the different functional pathway of microorganisms was only showed in jejunum, among which the metabolic and disease pathways of male ducks were higher, while gene pathways was lower. Conclusions The intestines of male ducks have higher development, nutrient absorption, fat deposition and metabolic capacity while their disease resistance was relatively weak, providing a basic reference for intestinal development and microorganism symbiosis of duck in different genders.

PO-227 Study On The Effect Of Exercise On Intestinal Flora And Its Mechanism

Objective To explore the relationship between exercise and intestinal microbes, and to analyze the effect of exercise on intestinal microflora to affect the health, in order to provide a theoretical basis for the study of the future exercise and the intestinal microorganism. Methods the PUBMED and Google academic articles were used to retrieve articles related to intestinal microorganism and exercise from June 1, 2008 to June 1, 2018. The key words: "Exercise" and "Microbiome (intestinal microorganism)". Inclusion criteria: (1) study on the correlation between intestinal flora and host.(2) The study of the effect of exercise intervention on intestinal flora. (3) exercise changes the intestinal flora and affects the physiological and pathological state of the host. A total of 76 Chinese and English related literatures were retrieved, and 32 articles were included in the final analysis according to the screening criteria. Results there are several important correlations between the intestinal microflora and the host: (1)the intestinal microorganism has the function similar to the endocrine organ, which can produce a large number of hormones in the body, release it into the blood and play its role in the distal organ. (2) the immune system components in the host are directly or indirectly regulated by microbes, such as the metabolites of microbes that induce the expression of immune cells, promote or inhibit the occurrence of inflammatory reactions.(3) Intestinal microbes affect the metabolism of the body and participate in the synthesis of vitamins and the absorption of calcium and magnesium plasma. The effect of exercise on intestinal flora is mainly reflected in the following aspects: (1) the general influence of exercise on the intestinal physiology; reducing the digestion time of food in the gastrointestinal tract, thus affecting the composition of the intestinal flora. Exercise reduces gastrointestinal blood flow and affects gastrointestinal endocrine changes. (2) There were great changes in the intestinal microflora of obese mice induced by high fat diet. Exercise could normalize the abnormal groups of the mice and improve the anxiety induced by high fat diet. (3) The mice in the exercise group showed a higher concentration of n-butyric acid than those in the lack of exercise, suggesting that the change in the intestinal microbial environment caused by exercise may be an important reason for the improvement of gastrointestinal diseases. (4) Exercise to improve cardiopulmonary endurance can increase the diversity of intestinal flora, and the diversity of intestinal flora is positively correlated with host health and other related indicators.(5) Exercise affects the number and diversity of intestinal microflora and leads to changes in certain specific strains, and the changes in most specific strains are closely linked to the health level of the body and the production of chronic diseases. Conclusions as a kind of non drug intervention with great potential and effective, exercise can regulate the number and diversity of the intestinal microorganism in the host, so as to improve the physiological and pathological state of the host and promote the health.