Measuring the process and rate of exogenous DNA degradation during digestion in mice

Abstract

This study aimed to perform qualitative and quantitative examination of DNA degradation during the digestion process in the mouse gut through PCR, qPCR and short tandem repeat (STR) analysis. Human blood leukocytes were gavaged into the digestive tract in mice. GAPDH, TH01, TPOX and D7S820 genes in the contents of the stomach and small intestine were analyzed with PCR and qPCR at various times pre- and post-gavage. Through STR analysis, 21 human genomic DNA loci were analyzed. The half-life of DNA degradation, and the relationship between the average peak area and digestion time were determined. The PCR results showed bands of amplified genes at pre-gavage (0 min) and post-gavage (40, 80 and 120 min) from the mouse stomach contents, whereas no DNA bands from small intestinal chyme were observed after gavage. The qPCR results revealed a significant decrease in DNA concentrations during 40–120 min in the mouse stomach after gavage. At 120 min, 85.62 ± 8.10% of the DNA was degraded, and the half-life of exogenous DNA degradation in the mouse stomach was 70.50 ± 5.46 min. At various digestion times, almost no target genes were detected in the mouse small intestinal chyme. STR analysis showed a decrease in allele numbers with bowel advancement in the small intestine in mice. The degradation of exogenous DNA was higher in the mouse stomach during the first 2 h, and almost complete degradation was observed within 40 min after entering the small intestine in mice.

Biomarkers of food intake and their relevance to metabolic syndrome

“…When studying the survival of exogenous DNA in the GI tract of mice, a recent study observed an approximate half-life of 71 minutes at the gastric phase; 316 we could not find any studies reporting the gastric half-life of exogenous RNA although we estimate it to be lower due to the decreased stability of a single nucleotide strand. 317 It may be assumed however that RNA may be stabilized in various food matrices given protection of plant cells that are not easily broken down during digestion, such as exosome-like nanoparticles of plant origin (ELN).…”

DNA methylation drives a new path in gastric cancer early detection: Current impact and prospects

“… 117 In practice, however, it is not feasible to use gastric juice DNA for molecular diagnosis because DNA is easily damaged by stomach acid (strongly acidic, pH less than 3). 118 , 119 Watanabe et al have proposed an alternative to the highly acidic gastric juice for molecular analysis using gastric washes, which is the flushing fluid (gastric mucosa and normal saline) obtained during routine endoscopy. Of the six hypermethylated genes ( RORA , ADAM23 , MLF1 , MINT25 , GDNF , and PRDM5 ), GDNF and MINT25 are the most sensitive biomarkers for early GC, and in terms of gastric washes, the MINT25 site has the best specificity (95.8%) and sensitivity (90%).…”

Fate of transgenic soybean DNA and immune response of broilers fed genetically modified DP-3Ø5423–1 soybean

“…Additionally, ingested dietary DNA and DNA fragments are partially degraded through the GIT by acids, enzymes, and microbial activities ( Zhu et al, 2004 ; Wiedemann et al, 2006 ). A recent study showed that approximately 86% of the exogenous DNA degraded in the stomach of mice 2 h after oral gavage and almost complete degradation was observed within 40 min after entering the small intestine ( Xing et al, 2022 ). Besides, the probability of detection of the short fragments in the GIT is higher in avian species due to the fast passage rate of the feed compared to mammals ( Klotz et al, 2002 ).…”