Investigating the role of perceived stress on bacterial flora activity and salivary cortisol secretion: A possible mechanism underlying susceptibility to illness
Open accessAbstract
This study examined the impact of academic stress on salivary cortisol concentrations and lactic acid bacteria activity. Whole, unstimulated saliva samples and faecal samples were collected from 23 healthy undergraduate students (23.0+/-6.8 years; range 18-44) over two 1-week periods: during the beginning of semester (low-stress baseline condition) and during the first week of exams (high-stress condition). Students also completed a series of questionnaires measuring perceived levels of stress, gastrointestinal symptoms, and nutritional intake. Significant findings indicated that faecal lactic acid bacterial levels were lower during the high-stress condition. Paralleling this, students rated perceived levels of stress as being greater during the exam period compared to the baseline condition. The findings from this study have provided further insight into the link between stress and gastrointestinal flora activity in humans.
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A connection has been established between the digestive tract and stress.
“Moreover, a connection has been established between the digestive tract and stress [291, 292].”
From International Society of Sports Nutrition Position Stand: Probiotics (2019) · cites this paper as [292]
In college students undergoing final examination stress, the relative concentration of lactic acid bacteria in feces decreases after the examination.
“A study of college students undergoing the stress of final examinations found a decrease in the relative concentration of lactic acid bacteria in feces after the examination122”
From The Gut Microbiome and the Brain (2014) · cites this paper as [122]
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References 43 · Cited by 192
- Authors
- Knowles, S. R., Nelson, E. A., & Palombo, E. A.
- Affiliations
- Swinburne University of Technology (AU)
- Corresponding author
- Knowles, Simon R.
- Venue
- Biological Psychology
- Publisher
- Elsevier BV
- Published
- 2008-02
- Volume
- 77
- Issue
- 2
- Pages
- 132-137
- ISSN
- 0301-0511 (ISSN-L)
- OpenAlex
- W2139240706
- Cited by
- 192
- References
- 43
- Citations by year
- 2026: 5 · 2025: 8 · 2024: 23 · 2023: 17 · 2022: 13 · 2021: 12 · 2020: 11 · 2019: 13 · 2018: 16 · 2017: 10 · 2016: 16 · 2015: 10 · 2014: 13 · 2013: 7 · 2012: 6
- FWCI
- 0.90
- Type
- journal article
- Language
- en
- Open access
- green
- figshare.com
- Licence
- Locations
- Biological Psychology (publishedVersion)
- PubMed (publishedVersion)
- Swinburne figshare (Swinburne University of Technology) (acceptedVersion)
- Figshare (submittedVersion, cc-by)
- Swinburne figshare (Swinburne University of Technology)
- Funders
- Swinburne University of Technology
- Topics
- Life Sciences › Neuroscience › Behavioral Neuroscience › Stress Responses and Cortisol
- Life Sciences › Agricultural and Biological Sciences › Food Science › Probiotics and Fermented Foods
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
- Keywords
- perceived stress, academic stress, salivary cortisol, lactic acid bacteria, gut microbiota, fecal bacteria, gastrointestinal symptoms, nutritional intake, disease susceptibility, undergraduate students, exam period
- MeSH terms
- Adult, Diet, Feces, Female, Humans, Hydrocortisone, Lactobacillus, Male, Surveys and Questionnaires, Saliva, Stress, Psychological, Colony Count, Microbial, Gastrointestinal Tract
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