Cedars Sinai Medical Center - Medically Associated Science and Technology Program West Hollywood, CA
Ava Hosseini, MPH1, Mohamad Rashid, 2, Gabriela Leite, PhD3, Gillian Barlow, PhD3, Gonzalo Parodi, 3, Maritza Sanchez, 3, Maya Pimentel, 3, Sarah Ayyad, 3, Alyson Fiorentino, 3, Christine Chang, RN3, Mark Pimentel, MD3, Ruchi Mathur, MD3 1Cedars Sinai Medical Center - Medically Associated Science and Technology Program, West Hollywood, CA; 2Cedars Sinai Medical Center - Medically Associated Science and Technology Program, Los Angeles, CA; 3Cedars Sinai - Medically Associated Science and Technology, Los Angeles, CA
Introduction: Tonsillar tissue is an important immune reservoir and serves as an early activator of the immune system. Despite the link with infection and immunity, to date there is no study examining the effect of tonsillectomy on the small bowel microbiome. Here, we compare small bowel microbial profiles in subjects with or without tonsillectomy.
Methods: The REIMAGINE study is a novel large-scale study using validated methods for duodenal aspirate collection and microbiome sequencing in subjects undergoing upper endoscopy without colon prep. Subjects were divided into 2 groups: Self-reported undergoing a tonsillectomy (T+), and those who did not undergo a tonsillectomy (T-). Groups were matched for sex, age ±5 years, and BMI ±3 kg/m2. Duodenal aspirates were collected, and microbial DNA isolated using the MagAttract PowerSoilDNA Kit. V3 and V4 libraries were sequenced on MiSeq. Reference based Operational Taxonomic Unit clustering was performed using SILVA v132 database. Taxonomic analyses were performed with CLC Microbial Genomics Module v.2.5 and MicrobiomeAnalyst. Blood was collected for inflammatory biomarkers and biochemical analysis, including lipid and glucose profiles.
Results: 253 subjects were included (T+, N=126, mean age = 62±15, mean BMI = 26.12±5.55) (T-, N=127, mean age = 63±13, mean BMI = 25.62±5.75). There was no significant difference in blood level of any analyte between groups. There was no statistical difference in duodenal microbial alpha-diversity (P >0.05) or beta-diversity (P >0.05) between the T+ group and T- group (Fig1a,b). The most prevalent phylum in the core duodenal microbiome of the T+ group was Firmicutes, followed by Actinobacteria and Proteobacteria. While Firmicutes was also the most prevalent phylum in the T- group, Proteobacteria moved up in rank to the second most prevalent phylum, and Actinobacteria dropped to third most prevalent. There were no major higher order taxonomic differences between T+ and T- groups (Fig1c). At genus level, Streptococcus (FC= 0.1, FDR P-value=1) (an organism known to infect the oropharynx) was not significantly different between groups. The only genus change observed was an increase in the relative abundance of Granulicatellain the T+ group (FC= 2.02, FDR P-value=0.01).
Discussion: Our findings demonstrate that history of tonsillectomy was associated with very few changes in the small bowel microbiome. Of note, organisms such as Streptococcus were not altered in subjects with prior tonsillectomy.
Figure: Figure 1. A) Alpha-diversity box plots comparing the duodenal microbial diversity in the Tonsillectomy group (T+), and the no Tonsillectomy group (T-), as determined using three different indices, Shannon’s, Simpson’s and Chao1. B) Principal Component Analysis (PCA) plot of the duodenal microbiome beta-diversity of Tonsillectomy group (T+) compared to no Tonsillectomy group (T-). C) Heat tree illustrating minimal changes to the microbiome in subjects who reported undergoing a tonsillectomy (T+) relative to those who did not (T-). Nodes represent taxonomic levels, and greater line thickness denotes greater relative abundance. Taxa with higher relative abundance in the T+ group when compared to the T- group are shown in red. Taxa with higher relative abundance in the T- group when compared to the T+ group are shown in blue. Taxa with similar relative abundance in both groups are shown in gray.
Disclosures:
Ava Hosseini indicated no relevant financial relationships.
Mohamad Rashid indicated no relevant financial relationships.
Gabriela Leite indicated no relevant financial relationships.
Gillian Barlow indicated no relevant financial relationships.
Gonzalo Parodi indicated no relevant financial relationships.
Maritza Sanchez indicated no relevant financial relationships.
Maya Pimentel indicated no relevant financial relationships.
Sarah Ayyad indicated no relevant financial relationships.
Alyson Fiorentino indicated no relevant financial relationships.
Christine Chang indicated no relevant financial relationships.
Mark Pimentel indicated no relevant financial relationships.
Ruchi Mathur indicated no relevant financial relationships.
Ava Hosseini, MPH1, Mohamad Rashid, 2, Gabriela Leite, PhD3, Gillian Barlow, PhD3, Gonzalo Parodi, 3, Maritza Sanchez, 3, Maya Pimentel, 3, Sarah Ayyad, 3, Alyson Fiorentino, 3, Christine Chang, RN3, Mark Pimentel, MD3, Ruchi Mathur, MD3. D0636 - History of Tonsillectomy Is Seen to Have a Minimal Impact on the Small Intestinal Microbiome, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.