The Effect of Diet and Exercise on Intestinal Integrity and Microbial Diversity in Mice

Background

The gut microbiota is now known to play an important role contributing to inflammatory-based chronic diseases. This study examined intestinal integrity/inflammation and the gut microbial communities in sedentary and exercising mice presented with a normal or high-fat diet.

Methods

Thirty-six, 6-week old C57BL/6NTac male mice were fed a normal or high-fat diet for 12-weeks and randomly assigned to exercise or sedentary groups. After 12 weeks animals were sacrificed and duodenum/ileum tissues were fixed for immunohistochemistry for occludin, E-cadherin, and cyclooxygenase-2 (COX-2). The bacterial communities were assayed in fecal samples using terminal restriction fragment length polymorphism (TRFLP) analysis and pyrosequencing of 16S rRNA gene amplicons.

Results

Lean sedentary (LS) mice presented normal histologic villi while obese sedentary (OS) mice had similar villi height with more than twice the width of the LS animals. Both lean (LX) and obese exercise (OX) mice duodenum and ileum were histologically normal. COX-2 expression was the greatest in the OS group, followed by LS, LX and OX. The TRFLP and pyrosequencing indicated that members of the Clostridiales order were predominant in all diet groups. Specific phylotypes were observed with exercise, including Faecalibacterium prausnitzi, Clostridium spp., and Allobaculum spp.

Conclusion

These data suggest that exercise has a strong influence on gut integrity and host microbiome which points to the necessity for more mechanistic studies of the interactions between specific bacteria in the gut and its host.     

THE IDENTITY OF THE SWEDE MIDGE, WITH NOTES ON ITS BIOLOGY

A brief historical summary is given of the literature concerning Contarinia nasturtii Kieffer, C. torquens de Meijere and C. geisenheyneri Riibsaamen, three gall midges (Cecidomyidae) which have been associated respectively with leaf damage on Brassica spp. in England, identical malformation on the Continent and swollen and closed flowers of Brassica spp. in Europe.
Following the discovery in England of the true Contarinia nasturtii causing swollen and closed flowers oiRorippa amphibia, preliminary experiments have shown that midges from this source will also cause similar damage to swede flowers and that they are the same species as those attacking R. amphibia blossom in the Netherlands.
Further preliminary experiments have shown that swede midge derived from rape leaf axils will also cause identical damage to radish flowers in addition to breeding successfully on the leaves of turnip, swede, cabbage and radish.
Male midges derived from Rorippa blossom have been mated with females from rape leaf axils, and their offspring have been reared on Rorippa flowers and on turnip leaves.
This biological evidence confirms the previous supposition based on morphological grounds that the swede midge is Contarinia nasturtii Kieffer and will cause either flower or leaf damage. Consequently, C. torquens de Meijere and C. geisenheyneri Riibsaamen must remain synonyms.
The shortest time for a generation (from parent to first offspring midge) to develop was 24–39 days in an unheated open glasshouse during June-July in 1949 at Harpenden. Under the same conditions, the shortest time for the next generation from late July to August was 29–32 days. C. nasturtii is the first Contarinia species in which unisexual families have been discovered.     

PERIPHERAL ARTERIOSCLEROSIS—Arterial Grafting Procedures—Indications and Results—Part I: Arteriosclerotic Aneurysms

In 32 cases aneurysms of the aorta and peripheral arteries were resected and replaced by grafts. The results from the use of homografts in 18 cases were more satisfactory than with the use of Ivalon in 14 cases. The abdominal aorta was the most frequent location of aneurysms.The current mortality rate of 5.5 per cent for resection of unruptured abdominal aneurysms indicates that resection and grafting are an effective means of reducing the high mortality of untreated aneurysms. Five ruptured aneurysms were excised, with a mortality rate of 40 per cent. The uniformly fatal outcome of untreated ruptured abdominal aneurysms makes it obligatory for the surgeon to operate immediately after the diagnosis is first made.     

The Epidemiology of Dental Diseases in the Elderly1

This paper summarizes and evaluates epidemiologic evidence on adult dental conditions with a focus on older adults. Information is presented on coronal caries; root caries; loss of teeth, attrition, abrasion, and erosion; periodontal diseases; and oral cancer. The author concludes that the oral health status of the elderly in the United States is essentially unknown. There are no recent, representative population base studies of oral conditions in the elderly. Studies of prevalence or incidence of oral diseases typically include few elderly persons or describe a select group of elderly who are at high risk. Furthermore, it is not really known whether the incidence and prevalence of coronal caries or root caries is actually increasing or is part of a cohort effect. While oral cancers have been shown to increase with age, there is no information as to whether their incidence rates are increasing. While, clinically, there are indications that attrition, abrasion and erosion are characteristics that are more likely to be seen in older adults, there is no information about their distribution in the population. There is evidence that loss of teeth is decreasing but nothing is known about the patterning of that loss. As for periodontal diseases, much work is needed to identify various syndromes that may be distinguished by their distribution in the population as well as determining whether periodontitis is a condition responsible for a majority of tooth loss or just the majority of tooth loss in a small high risk group. In addition, some suggestions are presented for future directions of research in this area.