The Gut Microbiome in Child Malnutrition.

Undernutrition affects almost 25% of all children under the age of 5 worldwide and underlies almost half of all child deaths. Child undernutrition is also associated with long-term growth deficits, in addition to reduced cognitive potential, reduced economic potential, and elevated chronic disease risk in later life. Dietary interventions alone are insufficient to comprehensively reduce the burden of child undernutrition and fail to address the persistent infectious burden of the disease. Although the role of infections is well recognized in the pathogenesis of undernutrition, an emerging body of evidence suggests that commensal microbial communities, known as the microbiome, also play an important role. The gut microbiome regulates energy harvesting from nutrients, growth hormone signaling, colonization resistance, and immune tolerance against pathogens, amongst other pathways critically associated with healthy child growth. Hence, disturbance of the normal gut microbial ecosystem via undernourished diets or unhygienic environments, especially in the early phases of life, may perturb these critical pathways associated with child growth, thereby contributing to child undernutrition. Here we discuss the emerging evidence for the role of the gut microbiome in child undernutrition and the potential for novel gut microbiota-targeted treatments to restore healthy child growth.

Nutrition status and Helicobacter pylori infection in patients receiving hemodialysis.

Chronic kidney disease (CKD) patients receiving hemodialysis (HD) often develop gastrointestinal abnormalities over their long treatment period. In general, prognosis in such patients is poor due to the development of protein-energy wasting (PEW). Therefore, it is important to clarify the etiology of PEW and to establish better strategies to deal with this condition. Chronic Helicobacter pylori (H. pylori) infection in the gastric mucosa has a close association with not only the development of peptic ulcer disease and gastric cancer, but is also associated with abnormal plasma and gastric mucosal ghrelin levels that are seen in malnutrition. It is unclear whether H. pylori infection of the gastric mucosa is directly associated with prognosis in HD patients by affecting ghrelin levels. Recent studies show that the prevalence of H. pylori infection in HD patients is significantly lower than in subjects with normal renal function. In the natural history of H. pylori infection in HD patients, the prevalence of infection decreases as the length of time on HD increases. The severity of gastric mucosal atrophy has been suggested as the major determinant of ghrelin levels in these patients, and eradication therapy of H. pylori improves nutritional status by increasing serum cholinesterase and cholesterol levels, especially in patients with mild-to-moderate gastric mucosal atrophy. Prompt H. pylori eradication to inhibit the progress of gastric atrophy may be required to prevent this decrease in ghrelin levels and subsequent PEW and improve the prognosis of HD patients by improving their nutritional status.

Agelas Wasting Syndrome Alters Prokaryotic Symbiont Communities of the Caribbean Brown Tube Sponge, Agelas tubulata.

The brown tube sponge Agelas tubulata (cf. Agelas conifera) is an abundant and long-lived sponge on Caribbean reefs. Recently, a disease-like condition, Agelas wasting syndrome (AWS), was described from A. tubulata in the Florida Keys, where prevalence of the syndrome increased from 7 to 35% of the sponge population between 2010 and 2015. In this study, we characterized the prokaryotic symbiont community of A. tubulata for the first time from individuals collected within the same monitoring plots where AWS was described. We also sampled tissue from A. tubulata exhibiting symptoms of AWS to determine its effect on the diversity and structure of prokaryotic symbiont communities. Bacteria from the phyla Chloroflexi and Proteobacteria, particularly the class Gammaproteobacteria, dominated the sponge microbiome in tissue samples of both healthy sponges and those exhibiting AWS. Prokaryotic community structure differed significantly between the diseased and healthy sponge samples, with greater variability among communities in diseased samples compared to healthy samples. These differences in prokaryotic community structure included a shift in relative abundance of the dominant, ammonia-oxidizing (Thaumarchaeota) symbionts present in diseased and healthy sponge samples. Further research is required to determine the functional consequences of this shift in microbial community structure and the causal relationship of dysbiosis and sponge disease in A. tubulata.

Microbiota's No Wasting Policy.

Schieber et al. demonstrate that a specific gut microbiota bacterial strain induces a host-mediated protection mechanism against inflammation-driven wasting syndrome. This salutary effect confers a net survival advantage against bacterial infection, without interfering with the host's pathogen load, revealing that host-microbiota interactions regulate disease tolerance to infection.

Disease tolerance mediated by microbiome E. coli involves inflammasome and IGF-1 signaling.

Infections and inflammation can lead to cachexia and wasting of skeletal muscle and fat tissue by as yet poorly understood mechanisms. We observed that gut colonization of mice by a strain of Escherichia coli prevents wasting triggered by infections or physical damage to the intestine. During intestinal infection with the pathogen Salmonella Typhimurium or pneumonic infection with Burkholderia thailandensis, the presence of this E. coli did not alter changes in host metabolism, caloric uptake, or inflammation but instead sustained signaling of the insulin-like growth factor 1/phosphatidylinositol 3-kinase/AKT pathway in skeletal muscle, which is required for prevention of muscle wasting. This effect was dependent on engagement of the NLRC4 inflammasome. Therefore, this commensal promotes tolerance to diverse diseases.

Microbiological quality of complementary foods and its association with diarrhoeal morbidity and nutritional status of Bangladeshi children.

BACKGROUND/OBJECTIVES: To examine the bacteriological quality of complementary foods (CF) and to correlate the results with diarrhoeal morbidity and nutritional status of Bangladeshi children aged 6-24 months. SUBJECTS/METHODS: A total of 212 CF samples were tested, of which 72 were collected immediately before the first time of feeding (≤ 1 h of food preparation) and 140 were collected at second/third time of feeding from 140 households located in urban and rural areas of Bangladesh. Anthropometry, food frequency data and demographic information of the children were collected. RESULTS: Of the first time feeding samples, 3% from each of urban and rural areas were found to be contaminated with faecal coliforms (FC) at ≥ 100 CFU/g. E. coli was isolated from 11% and 6% of samples, and B. cereus from 8% and 6% of samples from urban and rural areas, respectively. In contrast, 33% of the second/third time feeding samples from urban areas and 19% from rural areas were contaminated with FC at ≥ 100 CFU/g (P<0.05). E. coli was isolated from 40% and 39% of samples, and B. cereus from 33% and 26% of samples from urban and rural areas, respectively. Significantly high numbers of wasted rural children had CF with a high aerobic plate count, which was also significantly associated with diarrhoeal morbidity in children. CONCLUSIONS: Around 40% of CF samples were contaminated with E. coli, which was mainly attributable to food preparation practices. Consumption of contaminated CF appeared to be associated with a higher frequency of diarrhoea and malnutrition in children.

Multiple strains of Mycobacterium avium subspecies hominissuis infections associated with aborted fetuses and wasting in pigs.

A herd of pigs being reared for breeding and fattening, in which there had been incidences of abortion and wasting, reduced growth rates and an increase in mortality for the past year, were tested for Mycobacterium infection by pathological examinations, skin test, serology and Mycobacterium culture. In one placenta, and also in the lung tissues of fetuses, Ziehl-Neelsen staining revealed acid-fast bacilli in combination with infiltrations of neutrophils, macrophages and multinucleated giant cells. Acid-fast bacilli were also found in the mesenteric lymph nodes, liver and/or spleen and jejunum of pigs with wasting and in slaughtered animals. The specimen cultures were identified as Mycobacterium avium subspecies hominissuis using IS1245-specific PCR and IS1245 restriction fragment length polymorphism (RFLP). IS1245 RFLP revealed that the herd was infected with multiple M avium subspecies hominissuis strains belonging to at least two different clades. It is suggested that this infection may have played a more important role in the economic losses of the pig farm than had been assumed previously.

Occurrence of swine salmonellosis in postweaning multisystemic wasting syndrome (PMWS) affected pigs concurrently infected with porcine reproduction and respiratory syndrome virus (PRRSV).

Fourteen diseased pigs from four farms in which there had been an outbreak of salmonellosis were investigated. Granulomatous inflammation with depletion of lymphocytes was observed in the swollen lymph nodes in these pigs. Antigens to porcine circovirus type 2 (PCV2) were immunolabeled in the lesions along with detection of viral DNA as PCV2 by polymerase chain reaction (PCR). In addition, antigens to porcine reproductive respiratory syndrome virus (PRRSV) were immunodetected in the lungs and Salmonella Choleraesuis was isolated from the affected pigs. The nine salmonellosis affected pigs, five (55.6%) with salmonellosis and PMWS concurrently infected with PRRSV were much higher than those infected with salmonellosis and PMWS (22.2%) or with salmonellosis and PPPRV (22.2%).

Pathological and aetiological studies of multifocal interstitial nephritis in wasted pigs at slaughter.

Multifocal interstitial nephritis in pigs has been associated with several infectious agents. The objective of the present study was to investigate several different potential infectious agents associated with "white-spotted" kidneys in pigs suffering from wasting at slaughter (aged 6-8 months). Twenty-nine case kidneys (with a "white-spotted" gross appearance) classified into 3 macroscopic lesional grades, and 15 control kidneys (lacking gross lesions), were obtained from a pig abattoir. Laboratory analyses to detect potential associations with the aforementioned pathological condition with Leptospira spp., porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), and bacteria, were carried out. Microscopically, interstitial nephritis with a lymphofollicular inflammatory pattern (follicular nephritis) was observed in both case and control kidneys, with a higher frequency seen in the former ones. No leptospires were identified, although antibodies to the Pomona and Bratislava serovars were detected. Some pyogenic bacteria were also isolated from both case and control kidneys. PCV2 nucleic acid was only detected in 1 case kidney. PRRSV antigen was not found in any tested sample. Some pigs were tested positive for PPV by serology. Apparently, none of the studied agents were specifically associated as being the potential cause of the renal lesions in the studied wasted pigs. The fact that these chronic lesions may have been the consequence of a previous infection with one of these studied microorganisms, or more, and eventually with other non-tested infectious agents during the growing-finishing period, cannot be ruled out.

Abundant PrP(CWD) in tonsil from mule deer with preclinical chronic wasting disease.

A monoclonal antibody dot-blot assay was used to evaluate detergent lysates of tonsil tissue from mule deer to detect PrP(CWD), the marker for the cervid transmissible spongiform encephalopathy chronic wasting disease (CWD). Samples of formalin-fixed brain and tonsil tissues from mule deer were examined for PrP(CWD) using immunohistochemistry (IHC) with Mab F99/97.6.1, the gold standard for diagnosis of preclinical CWD. The contralateral tonsil from each of the 143 deer was prepared for confirmatory IHC and as a 10% (wt/vol) detergent lysate without purification or enrichment steps for monoclonal antibody dot-blot assay. PrP(CWD) was detected by dot-blot assay in 49 of 50 samples considered positive by IHC. Forty-eight of the positive samples were evaluated with a quantitative dot-blot assay calibrated with recombinant PrP. Tonsillar PrP(CWD) concentrations ranged from 34 to 1,188 ng per 0.5 mg starting wet weight of tissue. The abundant PrP(CWD) in mule deer tonsil will facilitate development and validation of high-throughput screening tests for CWD in large populations of free-ranging deer.

Postweaning multisystemic wasting syndrome of pigs in Korea: prevalence, microscopic lesions and coexisting microorganisms.

A retrospective study was performed on natural cases of postweaning multisystemic wasting syndrome (PMWS), recorded from January 1999 to December 2000, to determine the prevalence, microscopic lesions, and other coexisting pathogens associated with PMWS. PMWS is diagnosed based on three criteria: the presence of clinical signs (retardation of growth), characteristic microscopic lesions (granulomatous inflammation and inclusion body), and the presence of porcine circovirus (PCV)-2 within these lesions. One hundred and thirty three (8.1%) of the 1634 pigs submitted from 1243 pig farms were diagnosed for PMWS. The affected pigs were from 25 to 120 days old, the majority (78 cases, 58.6%) being 60 to 80 days old. PMWS occurred each month during the two-year study period, but the incidence peaked in May (38 cases, 28.6%), followed by April (18 cases, 13.5%) and June (13 cases, 9.8%). The most consistent and characteristic lesions were multifocal, granulomatous inflammation in lymph nodes, liver and spleen, characterized by infiltration of epithelioid macrophages and multinucleated giant cells. The majority of cases (113 cases, 85.0%) was dual infection with other pathogens. The combination of PCV-2 and Hemophilus parasuis (43 cases, 32.3%) was shown to be the most prevalent followed by PCV-2 and porcine reproductive and respiratory syndrome virus (39 cases, 29.3%). The consistent presence of PCV-2, but lower prevalence of other viral and bacterial pathogens in all pigs examined with PMWS, has led to the speculation that PCV-2 is the etiological agent causing PMWS.