Handling stress may confound murine gut microbiota studies

Cary R. Allen-Blevins, Xiaomeng You, Katherine Hinde, David A. Sela

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Background. Accumulating evidence indicates interactions between human milk composition, particularly sugars (human milk oligosaccharides or HMO), the gut microbiota of human infants, and behavioral effects. Some HMO secreted in human milk are unable to be endogenously digested by the human infant but are able to be metabolized by certain species of gut microbiota, including Bifidobacterium longum subsp. infantis (B. infantis), a species sensitive to host stress (Bailey & Coe, 2004). Expo- sure to gut bacteria like B. infantis during critical neurodevelopment windows in early life appears to have behavioral consequences; however, environmental, physical, and social stress during this period can also have behavioral and microbial consequences. While rodent models are a useful method for determining causal relationships between HMO, gut microbiota, and behavior, murine studies of gut microbiota usually employ oral gavage, a technique stressful to the mouse. Our aim was to develop a less-invasive technique for HMO administration to remove the potential confound of gavage stress. Under the hypothesis that stress affects gut microbiota, particularly B. infantis, we predicted the pups receiving a prebiotic solution in a less-invasive manner would have the highest amount of Bifidobacteria in their gut. Methods. This study was designed to test two methods, active and passive, of solution administration to mice and the effects on their gut microbiome. Neonatal C57BL/6J mice housed in a specific-pathogen free facility received increasing doses of fructooligosaccharide (FOS) solution or deionized, distilled water. Gastrointestinal (GI) tracts were collected from five dams, six sires, and 41 pups over four time points. Seven fecal pellets from unhandled pups and two pellets from unhandled dams were also collected. Qualitative real-time polymerase chain reaction (qRT-PCR) was used to quantify and compare the amount of Bifidobacterium, Bacteroides, Bacteroidetes, and Firmicutes. Results. Our results demonstrate a significant difference between the amount of Firmicutes in pups receiving water passively and those receiving FOS actively (p-value = 0.009). Additionally, we found significant differences between the fecal microbiota from handled and non-handled mouse pups. Discussion. From our results, we conclude even handling pups for experimental purposes, without gavage, may induce enough stress to alter the murine gut microbiota profile. We suggest further studies to examine potential stress effects on gut microbiota caused by experimental techniques. Stress from experimental techniques may need to be accounted for in future gut microbiota studies.

Original languageEnglish (US)
Article numbere2876
JournalPeerJ
Volume2017
Issue number1
DOIs
StatePublished - 2017

Fingerprint

intestinal microorganisms
pups
Bifidobacterium longum subsp. infantis
mice
Health Maintenance Organizations
breast milk
Human Milk
Firmicutes
fructooligosaccharides
digestive system
Bifidobacterium
Dams
dams (mothers)
pellets
methodology
Prebiotics
Deionized water
Polymerase chain reaction
Bacteroidetes
Bacteroides

Keywords

  • Bifidobacteria
  • Methods
  • Microbiota
  • Milk oligosaccharides
  • Mouse study

ASJC Scopus subject areas

  • Neuroscience(all)
  • Medicine(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

Allen-Blevins, C. R., You, X., Hinde, K., & Sela, D. A. (2017). Handling stress may confound murine gut microbiota studies. PeerJ, 2017(1), [e2876]. https://doi.org/10.7717/peerj.2876

Handling stress may confound murine gut microbiota studies. / Allen-Blevins, Cary R.; You, Xiaomeng; Hinde, Katherine; Sela, David A.

In: PeerJ, Vol. 2017, No. 1, e2876, 2017.

Research output: Contribution to journalArticle

Allen-Blevins, CR, You, X, Hinde, K & Sela, DA 2017, 'Handling stress may confound murine gut microbiota studies', PeerJ, vol. 2017, no. 1, e2876. https://doi.org/10.7717/peerj.2876
Allen-Blevins, Cary R. ; You, Xiaomeng ; Hinde, Katherine ; Sela, David A. / Handling stress may confound murine gut microbiota studies. In: PeerJ. 2017 ; Vol. 2017, No. 1.
@article{aced9c06bae846268b663880aa24097c,
title = "Handling stress may confound murine gut microbiota studies",
abstract = "Background. Accumulating evidence indicates interactions between human milk composition, particularly sugars (human milk oligosaccharides or HMO), the gut microbiota of human infants, and behavioral effects. Some HMO secreted in human milk are unable to be endogenously digested by the human infant but are able to be metabolized by certain species of gut microbiota, including Bifidobacterium longum subsp. infantis (B. infantis), a species sensitive to host stress (Bailey & Coe, 2004). Expo- sure to gut bacteria like B. infantis during critical neurodevelopment windows in early life appears to have behavioral consequences; however, environmental, physical, and social stress during this period can also have behavioral and microbial consequences. While rodent models are a useful method for determining causal relationships between HMO, gut microbiota, and behavior, murine studies of gut microbiota usually employ oral gavage, a technique stressful to the mouse. Our aim was to develop a less-invasive technique for HMO administration to remove the potential confound of gavage stress. Under the hypothesis that stress affects gut microbiota, particularly B. infantis, we predicted the pups receiving a prebiotic solution in a less-invasive manner would have the highest amount of Bifidobacteria in their gut. Methods. This study was designed to test two methods, active and passive, of solution administration to mice and the effects on their gut microbiome. Neonatal C57BL/6J mice housed in a specific-pathogen free facility received increasing doses of fructooligosaccharide (FOS) solution or deionized, distilled water. Gastrointestinal (GI) tracts were collected from five dams, six sires, and 41 pups over four time points. Seven fecal pellets from unhandled pups and two pellets from unhandled dams were also collected. Qualitative real-time polymerase chain reaction (qRT-PCR) was used to quantify and compare the amount of Bifidobacterium, Bacteroides, Bacteroidetes, and Firmicutes. Results. Our results demonstrate a significant difference between the amount of Firmicutes in pups receiving water passively and those receiving FOS actively (p-value = 0.009). Additionally, we found significant differences between the fecal microbiota from handled and non-handled mouse pups. Discussion. From our results, we conclude even handling pups for experimental purposes, without gavage, may induce enough stress to alter the murine gut microbiota profile. We suggest further studies to examine potential stress effects on gut microbiota caused by experimental techniques. Stress from experimental techniques may need to be accounted for in future gut microbiota studies.",
keywords = "Bifidobacteria, Methods, Microbiota, Milk oligosaccharides, Mouse study",
author = "Allen-Blevins, {Cary R.} and Xiaomeng You and Katherine Hinde and Sela, {David A.}",
year = "2017",
doi = "10.7717/peerj.2876",
language = "English (US)",
volume = "2017",
journal = "PeerJ",
issn = "2167-8359",
publisher = "PeerJ",
number = "1",

}

TY - JOUR

T1 - Handling stress may confound murine gut microbiota studies

AU - Allen-Blevins, Cary R.

AU - You, Xiaomeng

AU - Hinde, Katherine

AU - Sela, David A.

PY - 2017

Y1 - 2017

N2 - Background. Accumulating evidence indicates interactions between human milk composition, particularly sugars (human milk oligosaccharides or HMO), the gut microbiota of human infants, and behavioral effects. Some HMO secreted in human milk are unable to be endogenously digested by the human infant but are able to be metabolized by certain species of gut microbiota, including Bifidobacterium longum subsp. infantis (B. infantis), a species sensitive to host stress (Bailey & Coe, 2004). Expo- sure to gut bacteria like B. infantis during critical neurodevelopment windows in early life appears to have behavioral consequences; however, environmental, physical, and social stress during this period can also have behavioral and microbial consequences. While rodent models are a useful method for determining causal relationships between HMO, gut microbiota, and behavior, murine studies of gut microbiota usually employ oral gavage, a technique stressful to the mouse. Our aim was to develop a less-invasive technique for HMO administration to remove the potential confound of gavage stress. Under the hypothesis that stress affects gut microbiota, particularly B. infantis, we predicted the pups receiving a prebiotic solution in a less-invasive manner would have the highest amount of Bifidobacteria in their gut. Methods. This study was designed to test two methods, active and passive, of solution administration to mice and the effects on their gut microbiome. Neonatal C57BL/6J mice housed in a specific-pathogen free facility received increasing doses of fructooligosaccharide (FOS) solution or deionized, distilled water. Gastrointestinal (GI) tracts were collected from five dams, six sires, and 41 pups over four time points. Seven fecal pellets from unhandled pups and two pellets from unhandled dams were also collected. Qualitative real-time polymerase chain reaction (qRT-PCR) was used to quantify and compare the amount of Bifidobacterium, Bacteroides, Bacteroidetes, and Firmicutes. Results. Our results demonstrate a significant difference between the amount of Firmicutes in pups receiving water passively and those receiving FOS actively (p-value = 0.009). Additionally, we found significant differences between the fecal microbiota from handled and non-handled mouse pups. Discussion. From our results, we conclude even handling pups for experimental purposes, without gavage, may induce enough stress to alter the murine gut microbiota profile. We suggest further studies to examine potential stress effects on gut microbiota caused by experimental techniques. Stress from experimental techniques may need to be accounted for in future gut microbiota studies.

AB - Background. Accumulating evidence indicates interactions between human milk composition, particularly sugars (human milk oligosaccharides or HMO), the gut microbiota of human infants, and behavioral effects. Some HMO secreted in human milk are unable to be endogenously digested by the human infant but are able to be metabolized by certain species of gut microbiota, including Bifidobacterium longum subsp. infantis (B. infantis), a species sensitive to host stress (Bailey & Coe, 2004). Expo- sure to gut bacteria like B. infantis during critical neurodevelopment windows in early life appears to have behavioral consequences; however, environmental, physical, and social stress during this period can also have behavioral and microbial consequences. While rodent models are a useful method for determining causal relationships between HMO, gut microbiota, and behavior, murine studies of gut microbiota usually employ oral gavage, a technique stressful to the mouse. Our aim was to develop a less-invasive technique for HMO administration to remove the potential confound of gavage stress. Under the hypothesis that stress affects gut microbiota, particularly B. infantis, we predicted the pups receiving a prebiotic solution in a less-invasive manner would have the highest amount of Bifidobacteria in their gut. Methods. This study was designed to test two methods, active and passive, of solution administration to mice and the effects on their gut microbiome. Neonatal C57BL/6J mice housed in a specific-pathogen free facility received increasing doses of fructooligosaccharide (FOS) solution or deionized, distilled water. Gastrointestinal (GI) tracts were collected from five dams, six sires, and 41 pups over four time points. Seven fecal pellets from unhandled pups and two pellets from unhandled dams were also collected. Qualitative real-time polymerase chain reaction (qRT-PCR) was used to quantify and compare the amount of Bifidobacterium, Bacteroides, Bacteroidetes, and Firmicutes. Results. Our results demonstrate a significant difference between the amount of Firmicutes in pups receiving water passively and those receiving FOS actively (p-value = 0.009). Additionally, we found significant differences between the fecal microbiota from handled and non-handled mouse pups. Discussion. From our results, we conclude even handling pups for experimental purposes, without gavage, may induce enough stress to alter the murine gut microbiota profile. We suggest further studies to examine potential stress effects on gut microbiota caused by experimental techniques. Stress from experimental techniques may need to be accounted for in future gut microbiota studies.

KW - Bifidobacteria

KW - Methods

KW - Microbiota

KW - Milk oligosaccharides

KW - Mouse study

UR - http://www.scopus.com/inward/record.url?scp=85011278661&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85011278661&partnerID=8YFLogxK

U2 - 10.7717/peerj.2876

DO - 10.7717/peerj.2876

M3 - Article

AN - SCOPUS:85011278661

VL - 2017

JO - PeerJ

JF - PeerJ

SN - 2167-8359

IS - 1

M1 - e2876

ER -