Are intestinal parasites associated with obesity in Mexican children and adolescents?

Detection of Blastocystis sp. and Dientamoeba fragilis using conventional and molecular methods in patients with celiac disease

Blastocystis sp. and Dientamoeba fragilis are intestinal protists, which are common worldwide, but the pathogenic role of these organisms in gastrointestinal diseases is still controversial. This study aimed to investigate the frequency of Blastocystis sp. and D. fragilis in stool samples from adult patients with celiac disease (CD) by using conventional and molecular methods. A total of 75 patients with CD and 75 healthy individuals were included in this study. Fresh stool specimens collected from each individual were analyzed by conventional and molecular methods. The overall prevalence of Blastocystis sp. and D. fragilis was 41.3% (31/75) and 24% (18/75) in patients with CD, and 46.7% (35/75) and 13.3% (10/75) in healthy controls, respectively. There was no statistically significant difference in the prevalence of Blastocystis sp. and D. fragilis between CD patients and healthy individuals. Blastocystis sp. subtypes were identified in 20 CD and 16 control patients and the overall subtype distribution was observed as ST1 13.9%, ST2 30.6%, and ST3 55.6%. The prevalence of Blastocystis sp. and D. fragilis in adults with CD is similar to the prevalence of protozoa in healthy adults. In this study, the most prevalent Blastocystis subtype was ST3 and the most frequent allele was a34 in both CD patients and healthy individuals. No significant difference was found between the two groups in terms of the detection rates of Blastocystis sp. and D. fragilis, and it is thought that both protists may be colonisers of the intestinal microbiome.

Comorbidities involving parasitic diseases: A look at the benefits and complications

Parasitic infections acquired by the population cause substantial morbidity worldwide, with individuals from developing countries being most affected. Some parasites remain in the host for long periods, settling in different organs, manipulating the flow of nutrients and metabolites, and influencing the immune response, favoring their adaptation. The host attempts to counteract the metabolic and immunological alterations and the possible damage caused by infection. These metabolic and immunological changes experienced by the host can influence the progression of other existing morbidities or those that will be acquired in the future. Cancer and metabolic diseases are also frequent causes of morbidity in the world population. The large numbers of individuals affected by cancer and metabolic diseases and the high prevalence of morbidity caused by parasitic diseases favor the development of comorbidity involving these pathologies. This review provides an overview of major advances in research on cancer and metabolic diseases associated with parasitic infections. Information about hosts and parasites such as alterations of the immune response, metabolism and adaptation mechanisms of the parasites, and parasitic molecules with therapeutic potential is provided, as well as the beneficial results or complications related to the comorbidities discussed herein. We emphasize the need to conduct additional studies addressing comorbidities associated with parasitic infections to improve the understanding of the impact of this association on the progression of morbidities, as well as the possibility of the therapeutic use of and therapeutic approaches involving parasites.

Assessing the prevalence and risk factors associated with Entamoeba complex infection among the Orang Asli school children in Perak, Malaysia through molecular approach

This study performed a cross-sectional investigation on the prevalence of Entamoeba complex infection comprising Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii and their associated risk factors among the Orang Asli school children in three districts in Perak, Malaysia. Stool samples collected from 544 school children aged between 7 and 12 years old were examined through the nested multiplex PCR assay. The univariate and multivariate regression analyses were then carried out to determine the risk factor associated with Entamoeba complex infection. The overall prevalence of Entamoeba complex infections (E. histolytica, E. dispar and E. moshkovskii) was 21.3% (116/544). Most positive school children were infected with E. moshkovskii (10.7%; 58/544), followed by E. dispar (9.0%; 49/544) and E. histolytica (5.0%; 27/544). Not washing their hands after using the toilet was identified as the only significant risk factor for E. histolytica. The significant risk factors associated with E. moshkovskii infection included children within the age of 10-12 years old, with high BMI, living with working and non-educated mothers, no toilet in the house, not washing their hands after using the toilet, and fever. On the other hand, drinking water from the river, well, and rain was associated with a decreased risk of E. dispar infection. In conclusion, this study showed a high prevalence of Entamoeba spp. infections among the Orang Asli school children in Perak, Malaysia. Addressing the identified risk factors coupled with a holistic approach in breaking the transmission of Entamoeba complex can help improve their quality of life.

Association between Intestinal Parasite Infections and Proxies for Body Composition: A Scoping Review

It has long been recognized that intestinal parasite infections and undernutrition are closely linked. However, little is known about the role of intestinal parasite infections (IPIs), or parasite clearance, in these processes. The aim of this scoping review was to summarize published evidence on the association between IPIs and body composition. PRISMA guidelines, PubMed/MEDLINE, EMBASE and Cochrane Library databases were searched up until June 2021. Studies reporting on IPIs in relation to (proxies for) body composition were eligible. Study quality and risk of bias were assessed using Joanna Briggs Institute (JBI) critical appraisal tools. Twenty-four studies were included, two Randomized Control Trials (RCTs) and 22 observational. Most observational studies showed IPIs to be associated with lower Body Mass Index (BMI) or being underweight as proxies for body composition. One RCT showed no effect of antiparasitic treatment on body composition, while the other one showed a significant post-treatment increase in body fat, as measured by BMI z-scores and skinfolds. This review lends support to distinct associations between IPIs and body composition. More longitudinal studies are needed using direct measures of body composition to investigate whether weight gained after antiparasitic treatment concerns an increase in body fat or healthy weight gain.

Infant Anthropometry and Growth Velocity Before 6 Months are Associated with Breastfeeding Practices and the Presence of Subclinical Mastitis and Maternal Intestinal Protozoa in Indigenous Communities in Guatemala

BACKGROUND

The possibility that maternal health status and breastfeeding practices contribute to growth faltering before 6 mo is underexplored.

OBJECTIVES

This longitudinal study investigated whether indicators of subclinical mastitis (SCM) and breast inflammation, maternal fecal-oral contamination, and/or breastfeeding practices were associated with infant anthropometry or growth velocity before 6 mo.

METHODS

Indigenous Mam-Mayan mother-infant dyads (n = 140) were recruited. Breast milk was collected at early (<6 wk) and established (4-6 mo) lactation when maternal and infant anthropometry were measured. Milk Na:K ratio as an indicator of SCM and concentrations of 4 proinflammatory cytokines were measured. Maternal stool samples were examined for the presence of intestinal parasites including nonpathogenic protozoa (Endolimax nana, Iodamoeba bütschlii, Entamoeba coli, Blastocystis hominis). Questionnaires characterized breastfeeding and hygiene practices. Multiple linear regression identified factors associated with infant growth attainment [weight-for-age z-score (WAZ), length-for-age z-score (LAZ), and head circumference-for-age z-score (HCAZ)] and growth velocity (expressed as change per day from early to established lactation). Multiple logistic regression identified factors associated with increased odds of underweight, stunting, and low head circumference at both lactation stages.

RESULTS

A higher Na:K ratio, individual nonpathogenic protozoa, and specific breastfeeding and hygiene practices were associated with impaired growth before 6 wk and at 4-6 mo in exclusively breastfed infants. Growth velocity for weight was inversely associated with Entamoeba coli but cranial growth was associated positively with Iodamoeba bütschlii whereas feeding colostrum in early lactation was protective and decreased the odds of an HCAZ < -2 SD. Finally, the presence of SCM in early lactation increased the likelihood of both WAZ < -2 SD and LAZ < -2 SD by 6 wk.

CONCLUSIONS

Prevention of SCM can improve early infant weight, but measures that promote the feeding of colostrum and reduce exposure to fecal-oral contamination might be required to minimize infant growth faltering in breastfed infants.