Lactobacillus (Limosilactobacillus) reuteri: a probiotic candidate to reduce neonatal diarrhea in calves

Karin Schwaiger; Julia Storch; Christoph Bauer; Johann Bauer

doi:10.3389/fmicb.2023.1266905

Lactobacillus (Limosilactobacillus) reuteri: a probiotic candidate to reduce neonatal diarrhea in calves

Front Microbiol. 2023 Oct 3:14:1266905. doi: 10.3389/fmicb.2023.1266905. eCollection 2023.

Authors

Karin Schwaiger¹, Julia Storch², Christoph Bauer³, Johann Bauer⁴

Affiliations

¹ Institute for Food Safety, Food Technology and Veterinary Public Health, Unit of Food Hygiene and Technology, University of Veterinary Medicine, Vienna, Austria.
² Veterinary Office Landratsamt Fürstenfeldbruck, Fürstenfeldbruck, Germany.
³ Department of Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Freising, Germany.
⁴ Chair of Animal Hygiene, School of Life Sciences, Technical University of Munich, Freising-Weihenstephan, Germany.

Abstract

Background: Diarrhea in newborn calves is considered life-threatening and results in large economic losses in dairy farms. Lactobacilli generally play an important role in intestinal health, and Lactobacillus (Limosilactobacillus; L.) reuteri is the dominant Lactobacillus species in the feces of healthy calves during the first week of life. In calves with diarrhea on day 2 postpartum, lactobacilli are significantly reduced even up to 24 h before the onset of clinical signs. Since the probability of occurrence of diarrheal disease decreases as the L. reuteri count in the feces increases, oral administration of this species might have a protective effect against diarrhea.

Objective: These studies were designed to demonstrate whether oral administration of preselected L. reuteri isolates can reduce the incidence of diarrhea in newborn calves on dairy farms.

Microorganisms: 46 L. reuteri isolates from 2-day-old healthy calves were available from a previous study.

Animals: 170 newborn calves of Simmental breed of 10 dairy farms in Bavaria (Germany), were included in the study; of 166 animals the data could be evaluated.

Methods: Microbiological (antibiotic sensitivity test, acid and bile salt stability test, antimicrobial activity of the supernatants), molecular biological (PCR, RAPD-PCR) and toxicological methods (MTT test) were used to select and to characterize suitable L. reuteri isolates. The administration of a suspension of two selected L. reuteri isolates (6-8 × 10⁸ colony forming units per day) to calves was performed from day 2 to day 5 after birth in a double-blinded placebo-controlled study. Clinical monitoring of the calves continued until the 14th day of life.

Results: Out of 46 L. reuteri isolates, only 2 met the set criteria and were used in the feeding trial. In the placebo group, 44 of 83 calves developed diarrhea within the first 2 weeks of life, whereas in the L. reuteri group this was only the case in 31 of 83 animals (p < 0.05).

Conclusion: L. reuteri appears to be of particular importance for the intestinal health of newborn calves. The diarrhea protective effect could be even more pronounced if an improved administration regimen is developed in terms of start, frequency, and duration.

Keywords: Lactobacillus; Limosilactobacillus; calf; diarrhea; protection; reuteri.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was funded by the Bavarian Research Foundation and financially supported by Trouw Nutrition. The funder was not involved in the study design, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.