Effect of stomach acid on probiotics

Probiotics are live microorganisms taken orally that are said to deliver health benefits. Clearly, to have an effect they need to reach the relevant portion of the gut. In horses, this is thought to be the large intestine – the caecum and colon. 

 It is recognised that probiotics may be adversely affected by the acid conditions in the stomach. Some products for human use are presented with enteric protection to help them survive the proximal gastrointestinal tract.

 

A study by Ana Berreta and colleagues at Washington State University, looked at the effect of the equine gastrointestinal tract on equine probiotics. The work is reported in the Journal of Equine Veterinary Science.

 

(c) Sharon Kingston Dreamstime.com

In the laboratory study, they assessed the viability of eleven commercially available equine probiotic products in
conditions of acidity designed to mimic those in the stomach and the small intestine.

 

The research team mixed each of 11 of the probiotics with hydrochloric acid at pH2 (to mimic conditions in the stomach). After 30 minutes the pH was raised to 6.9 and enzymes and electrolytes were added to mimic conditions in the small intestine. Then two hours later they cultured each mixture and used mass spectrometry to identify and quantify the microorganisms present. 

 

The experiment was repeated using an initial pH 4 (to represent the conditions in the stomach when proton pump inhibitors such as omeprazole were being used). 

 

They compared these results with those obtained using probiotics straight from the packet.

 

They found that the gastric pH of 2 adversely affected micro-organisms in six of 11 probiotics. Four of the probiotics had at least one micro-organism that was adversely affected when the pH was increased to 4.0.

 

The microorganism that was most commonly adversely affected by conditions in the virtual gastro-intestinal tract was Enterococcus faecium. In contrast, Saccharomyces cerevisiae (present in one product tested) actually increased significantly in number after exposure to both pH2 and pH4.

 

None of the probiotics tested matched their label claim - all of them contained micro-organisms not listed on the label.

 

The authors conclude that passage through the proximal gastro-intestinal tract may negatively impact the survival of some microorganisms. They suggest that enteric protection should be considered to improve microorganism viability in equine probiotics.

 

For more details, see:

 

Effect of the equine proximal gastrointestinal tract on probiotic viability

A Berreta, JJ Kopper, TL Alexander, CJ Kogan, CR Burbick

Journal of Equine Veterinary Science (2021) 104

https://doi.org/10.1016/j.jevs.2021.103671

New colic researched planned

(c) Maria Itina Dreamstime.com

 Colic features heavily in research projects being supported by the Morris Animal
Foundation in 2022.

New equine health studies to receive funding this year include:

• Studying Intestinal Inflammation

Two research teams will take different approaches to investigate the interaction between inflammation and gut motility, to assist in developing methods of preventing ileus (reduced gut motility) after colic surgery. These approaches could dramatically assist recovery and shorten hospitalization times.

• Understanding Risk Factors for Colic Secondary to Transportation

Researchers will look for colic risk factors associated with transportation, to develop better management recommendations for horses requiring transport.

• Helping Underserved Communities Recognize Early Signs of Colic

Researchers will develop an educational program for horse owners and enthusiasts in underserved communities in Colombia to improve early recognition of colic, a key component of successful treatment.

• New Prognostic Test for Postoperative Complications

Researchers will search for biomarkers to identify horses at higher risk for postoperative surgical complications as a first step toward a new prognostic test.

“Colic consistently ranks among the top health concerns of horse owners and veterinarians,” said Dr. Janet Patterson-Kane, Chief Scientific Officer. “We decided to focus on this topic in this year’s equine call for proposals to advance our understanding of intestinal disease associated with colic and ultimately assist in improving outcomes for horses around the world.”

For more details, see:

https://www.morrisanimalfoundation.org/article/new-equine-colic-studies-2022

Risk of inhaled particles during powered equine dentistry

(c) Chelle 129 Dreamstime.com

Powered equine dentistry places operators at risk of inhaling unsafe levels of inorganic particulate
matter, according to a recent study.

Motorised equipment is regularly used by equine veterinarians and dental technicians when carrying out routine equine dental procedures. Research suggests that particulate matter produced during the process poses possible health risks to the operators through inhalation of aerosolised particles.

 

The study, conducted at Bristol University, investigated the dust particles produced during the motorised rasping of horses’ teeth. Sam Bescoby, in the Langford Vets Equine Department at the University, was lead author in the study, which used cadaver heads that were rasped under standardised conditions.

 

A full report on the work is published in the Equine Veterinary Journal.

 

The authors found that both water-cooled and non-cooled motorised equipment produced particle levels (4.48mg/m³and 7.94 mg/m³ respectively) that were higher than the workplace exposure limit (WEL). (The time-weighted average (TWA) limit set by the Health and Safety Executive in the UK is 4mg/m³)

 

The particles produced were of a range of sizes that could reach all levels of the human respiratory tract. Analysis of the dust found not only calcium and phosphorus from the teeth but also tungsten, aluminium and iron.

 

The researchers found that surgical masks reduced the exposure levels to some extent. However, the FFP3 mask was recommended as more effective than the standard surgical face mask.

 

They advise that a suitable face mask should be worn to reduce exposure to dust particles to within acceptable limits.

 

This study looked at only the inorganic particulate matter. The authors suggest that further work on the biological component of the particulate matter is needed.

 

 

For more details, see: 

 

Quantitative and qualitative analysis of operator inhaled aerosols during routine motorised equine dental treatment.

S.R Bescoby, SA Davis, M Sherriff, AJ Ireland

Equine Vet J (2021) 53, 1036 – 1046

https://doi.org/10.1111/evj.13379

Antibacterial actions of mesenchymal stromal cells

Infected wound healing could be helped by factors secreted by mesenchymal stromal cells. 

Mention “bacteria” and we tend to think of the individual microorganisms that we see growing in laboratory cultures (the so-called “planktonic” forms.) However, in nature it is more common for bacteria to form biofilms – communities of different microbes that become embedded in a slimy extracellular matrix. Biofilms protect the microbes from both antibacterial substances and the immune response of the host.

Biofilms contribute to chronic inflammation and delayed healing of wounds, and are not readily detectable using current routine diagnostic methods. However, biofilm infections should be suspected in equine limb wounds that are not healing as expected. Treatment is based on repeated debridement and application of topical antimicrobial therapy.

 

Mesenchymal stromal cells (MSCs) are cells, isolated from different sites, that can differentiate into other types of cells. They take part in the inflammatory, proliferative, and remodelling phases of tissue repair.

 

Previous work has shown that secretions from MSCs promote wound repair by stimulating fibroblast migration in the skin and promoting development of new blood vessels. They also have antibacterial properties. 

 

A recent study looked at the effect of mesenchymal stromal cells on biofilms.

 

Research by Charlotte Marx and colleagues at the Cornell University College of Veterinary Medicine looked at the effect of mesenchymal stromal cells on biofilms, using an equine skin explant model.

 

They found that secreted factors from equine MSC (collectively referred to as the MSC secretome) significantly decreased the viability of methicillin-resistant Staphylococcus aureus (MRSA) in mature biofilms.

 

They also showed that equine MSCs secrete the cytokine CCL2 that boosts the antimicrobial activity of equine keratinocytes by stimulating the production of cathelicidin and ß-defensin.

 

Reporting their work in the journal Tissue Engineering and Regenerative Medicine, they conclude: “Collectively, these data contribute to our understanding of the MSC secretome's anti-microbial properties, both directly by killing bacteria and indirectly by stimulating immune responses of surrounding resident skin cells, thus further supporting the value of MSC secretome-based treatments for infected wounds.”

 

 

For more details, see:

 

Mesenchymal stromal cell-secreted CCL2 promotes antibacterial defense mechanisms through increased antimicrobial peptide expression in keratinocytes 

Charlotte Marx, Sophia Gardner, Rebecca M. Harman, Bettina Wagner, Gerlinde R. Van de Walle.

Tissue Engineering and Regenerative Medicine (2021) Vol 10 (12) pp1666-1679

https://dx.doi.org/10.1002/sctm.21-0058

What are omics?

Photo: Rossdales Laboratories

 You may have noticed that “-omics” are cropping up with increasing regularity. What are they, and why are they important?

Omics refers to a field of biological sciences including genomics (studying the complete genetic makeup, the DNA, of an organism), transcriptomics (studying RNA), proteomics (proteins) and metabolomics (metabolites). Omics encompasses powerful tools that are rapidly transforming our understanding of disease. 

 

To celebrate how the omics disciplines are making a significant impact on equine veterinary medicine, the Equine Veterinary Journal (EVJ) is giving free access to a Virtual Issue of recent articles covering genomics, transcriptomics, proteomics and metabolomics .

 

The virtual issue has been co-ordinated by EVJ’s Associate Editors Mandy Peffers and Pablo Murcia, with guest editors Carrie Finno, James Anderson and Macarena Sanz.

 

“The relationship between microbiota, health and disease in humans has been investigated for years but similar studies in horses have only been recently published,” says Macarena Sanz, whose editorial navigates five articles on this topic.

 

She concludes: “Although equine microbiomics is in its infancy, new studies will provide an exciting insight into the nature of the equine microbiome and its potential role in the development of disease. Knowledge of the microbiome is key to advancing prophylactic, diagnostic and therapeutic options and to better understanding the pathophysiology of equine conditions.”

 

James Anderson prefaces five papers on advances made in equine medicine within the disciplines of proteomics, metabolomics and lipidomics (a subset of metabolomics). He concludes: “Omics technologies have enhanced our knowledge of the molecular world and provided fascinating insight into the composition and functions of these components across a range of different animal species. Particularly for equine science and medicine they have increased our understanding of molecular changes in disease and informed the development of diagnostic tests. Although still in its infancy within equine veterinary science, this field looks likely to have a significant impact in the coming years.”

 

Mandy Peffers, Associate Editor of the EVJ said: “It is exciting to see how the equine veterinary sector is now keeping pace with human medicine in the omics revolution. As we continue to advance, there will be more tools at our disposal for the diagnosis and treatment of equine disease.”

 

The Virtual Issue is available to all at 

 

https://beva.onlinelibrary.wiley.com/doi/toc/10.1001/(ISSN)2042-3306.OmicsEVJ

Photo competition to promote equine research

 

Keen photographers in North America are invited to enter an online photo contest hosted by Grayson-Jockey Club Research Foundation.

The contest opens February 1, and entries will be accepted until February 28. Entrants are encouraged to submit original photos of horses representing all breeds, backgrounds, and disciplines on Grayson's website.

 

"Our photo contest has proved to be a popular way for horse lovers to spread awareness of the importance of equine veterinary research," said Jamie Haydon, president of Grayson-Jockey Club Research Foundation.

Grayson-Jockey Club Research Foundation has provided more than $30.6 million to fund 397 projects at 45 universities in North America and overseas.

For more details, and to enter the competition, go to:

http://grayson-jockeyclub.org/default.asp?section=2&area=PHOTOINFO

Impact of research on horses' lives

 The next offering in the equine health seminar series from the University of Saskatchewan’s
Western College of Veterinary Medicine on February 8^th is a virtual panel discussion that will explore the benefits of research on horses’ health. 

Topics to be covered include: What's new in horse health research at the WCVM and across Western Canada? What are key horse health problems that researchers are working to solve? If you could choose a health issue that needs further research, what would it be? 

 

The equine health seminar series is open to everyone in the horse community. While there is no cost to attend, you must register in advance.

 

Further details of this, and future seminars, together with recordings of previous talks, are available at:

 

https://wcvm.usask.ca/education/equine-seminars.php#Overview