Tara J Cepon-Robins1, Theresa E Gildner2, Joshua Schrock3, Geeta Eick3, Ali Bedbury3, Melissa A Liebert4, Samuel S Urlacher5,6, Felicia C Madimenos7, Christopher J Harrington3, Dorsa Amir8, Richard G Bribiescas9, Lawrence S Sugiyama3, James J Snodgrass3. 1. Department of Anthropology, University of Colorado, Colorado Springs, Colorado. 2. Department of Anthropology, Dartmouth College, Hanover, New Hampshire. 3. Department of Anthropology, University of Oregon, Eugene, Oregon. 4. Department of Anthropology, Northern Arizona University, Flagstaff, Arizona. 5. Department of Evolutionary Anthropology, Duke University, Durham, North Carolina. 6. Department of Anthropology, Baylor University, Waco, Texas. 7. Department of Anthropology, Queens College - City University of New York, Queens, New York. 8. Department of Psychology, Boston College, Chestnut Hill, Massachusetts. 9. Department of Anthropology, Yale University, New Haven, Connecticut.
Abstract
OBJECTIVES: Little research exists documenting levels of intestinal inflammation among indigenous populations where exposure to macroparasites, like soil-transmitted helminths (STHs), is common. Reduced STH exposure is hypothesized to contribute to increased prevalence of elevated intestinal inflammation in wealthy nations, likely due to coevolutionary histories between STHs and human immune systems that favored anti-inflammatory pathways. Here, we document levels of intestinal inflammation and test associations with STH infection among the Shuar of Ecuador, an indigenous population undergoing socioeconomic/lifestyle changes that influence their hygienic environment. We predict that fecal calprotectin (FC; a measure of intestinal inflammation) will be lower in STH infected individuals and that FC will be negatively associated with infection intensity. METHODS: Stool samples to analyze FC levels and STH infection were collected from 69 Shuar participants (ages 5-75 years). Children (<15 years) and adults (15+ years) were analyzed separately to understand the role of exposure in immune system development and the intestinal inflammatory response. RESULTS: Two species of STH were present: Ascaris lumbricoides and Trichuris trichiura. The relationships between infection and intestinal inflammation were age- and species-specific. While no significant relationships were found among adults, children who were singly infected with T. trichiura had lower FC levels than uninfected children. Infection intensity was not significantly associated with FC in children or adults. CONCLUSIONS: These preliminary results provide limited support for our hypotheses, documenting tentative age- and species-specific associations between FC and infection status. Findings may point to the importance of species-specific STH exposure during immune system development.
OBJECTIVES: Little research exists documenting levels of intestinal inflammation among indigenous populations where exposure to macroparasites, like soil-transmitted helminths (STHs), is common. Reduced STH exposure is hypothesized to contribute to increased prevalence of elevated intestinal inflammation in wealthy nations, likely due to coevolutionary histories between STHs and human immune systems that favored anti-inflammatory pathways. Here, we document levels of intestinal inflammation and test associations with STHinfection among the Shuar of Ecuador, an indigenous population undergoing socioeconomic/lifestyle changes that influence their hygienic environment. We predict that fecal calprotectin (FC; a measure of intestinal inflammation) will be lower in STHinfected individuals and that FC will be negatively associated with infection intensity. METHODS: Stool samples to analyze FC levels and STHinfection were collected from 69 Shuar participants (ages 5-75 years). Children (<15 years) and adults (15+ years) were analyzed separately to understand the role of exposure in immune system development and the intestinal inflammatory response. RESULTS: Two species of STH were present: Ascaris lumbricoides and Trichuris trichiura. The relationships between infection and intestinal inflammation were age- and species-specific. While no significant relationships were found among adults, children who were singly infected with T. trichiura had lower FC levels than uninfected children. Infection intensity was not significantly associated with FC in children or adults. CONCLUSIONS: These preliminary results provide limited support for our hypotheses, documenting tentative age- and species-specific associations between FC and infection status. Findings may point to the importance of species-specific STH exposure during immune system development.
Authors: Chandni Patel; Ladina Keller; Sophie Welsche; Jan Hattendorf; Somphou Sayasone; Said M Ali; Shaali M Ame; Jean Tenena Coulibaly; Eveline Hürlimann; Jennifer Keiser Journal: EClinicalMedicine Date: 2021-01-30