Three questions to keep in mind when evaluating probiotics

As animal production has evolved over the years, feed additives have also evolved to support animal performance. Additionally, the scope of these additives has broadened beyond technical performance to include features such as Salmonella control. This is not surprising; Salmonella is reported as a causative agent for over 91000 cases of human disease in the European Union each year. As a result, the bacterium represents an annual economic cost of up to EUR 3 billion (EFSA, 2019).

Probiotics are one type of feed additive, defined as “viable strains of strictly selected microorganisms which, when administered in adequate amounts, confer a health benefit on the host” (FAO, 2002; ISAPP, 2013). As explained by Markowiak and Śliżewska (2018), the above definition only applies to formulas or products that comply with strictly defined criteria, such as having an appropriate count of viable cells or spores and having beneficial effects on the gastrointestinal tract.

When evaluating a probiotic strain, it is always important to keep three questions in mind:

1. What does the probiotic do?
2. Where will the probiotic exert its effect?
3. Can the probiotic easily be used in standard feed manufacturing?

These questions were recently applied to Clostridium butyricum, a novel and exciting probiotic on the European market.

What does the probiotic do?

The mode of action of Clostridium butyricum is multifactorial, but one of the most interesting aspects is its capacity to produce butyric acid (Cao et al., 2012). The multiple positive direct and indirect effects of this short chain fatty acid are well documented (as reviewed by Moquet, 2018):

• Increased nutrient digestibility
• Modified intestinal microbiota
• Improved epithelial integrity
• Stimulated immunity

Butyric acid can also directly or indirectly act on tissue development and repair and is linked to the hormone–neuro–immune system (Guilloteau et al., 2010). Apart from these benefits related to technical performance, it also plays a major role in the mitigation of pathogens including Salmonella (Bedford and Gong, 2018).

Where will the probiotic exert its effect?

Clostridium butyricum is an obligate anaerobe, meaning it will be active where oxygen concentrations are reduced. As such, it primarily produces butyric acid in the hindgut. This location is not easily reached by traditional butyrates incorporated directly into the feed, as they are utilised rapidly in the initial parts of the gastrointestinal tract, even in their coated or protected forms (Moquet, 2018).

There are two interesting aspects to the hindgut as a location. Firstly, it is the primary site for Salmonella proliferation. Secondly, specific butyric acid receptors are present on the colonocytes in the hindgut (Guilloteau et al., 2010). These are capable of efficiently utilising butyric acid and oxygen to produce ATP (adenosine triphosphate, energy). Consequently, oxygen is utilised in the tissue and not released into the lumen, whilst at the same time energy is provided for the animal. This is important for Salmonella mitigation as the bacteria requires oxygen to thrive and proliferate effectively in the lumen. As shown by Rivera-Chávez et al. (2016) it is therefore crucial to maintain butyrate-producing Clostridium bacteria populations, providing butyrate to achieve exactly this.

Can the probiotic easily be used in standard feed manufacturing?

As a spore-former, Clostridium butyricum can protect itself from unfavourable environmental conditions for prolonged periods of time. In this spore form, otherwise detrimental damages coming from exposure to heat, radiation, toxic chemicals/antibiotics and pH extremes will have no or very limited impact on the viability of the probiotic (Sella et al., 2014). The practical benefits are that Clostridium butyricum spores can withstanding feed production processes easily, can be stored for prolonged periods of time, and can pass through the initial stages of the gastrointestinal tract without becoming damaged (Huvepharma, 2019).

Keeping the questions and answers above in mind, Clostridium butyricum occupies a unique space in today’s probiotic market, with benefits extending beyond technical performance enhancements. This potential was realised by Huvepharma, leading to the formulation of Miya-Gold® and Top Gut®, single strain probiotic products containing a unique strain of Clostridium butyricum. Currently these two probiotics are the only European registered products containing Clostridium butyricum, highlighting Huvepharma’s unique position in the feed additive market.

For more information about Huvepharma’s range of probiotics, visit the website or contact [email protected].

References are available on request.