Imbalances in the intestinal microbiota are linked to the development of various diseases. As a result, there has been growing interest in using prebiotics, probiotics, and postbiotics to modulate the gut microbiome. Postbiotics refer to substances released or produced through the metabolic activity of microorganisms that exert beneficial effects on the host, either directly or indirectly. Since postbiotics do not contain live microorganisms, the risks typically associated with their consumption are significantly reduced.
In this review, we critically examine current literature on postbiotics, focusing on their mechanisms of action and potential applications in performance trials. We highlight their distinct benefits compared to live probiotics, with the goal of maximizing the effectiveness of postbiotics in target animals. The review explores their key components and advantages related to diet and gut health, emphasizing their role in supporting animal production—particularly in poultry. Relevant studies are referenced to illustrate the immunomodulatory, antimicrobial, anti-inflammatory, and antioxidant properties of postbiotics, as well as their overall impact on productivity and health in animal systems.
How to distinguish postbiotics and their benefits compared to live probiotics?
Postbiotics are metabolic by-products produced by bacteria (exogenous postbiotics). They include non-viable bacterial components and substances such as short-chain fatty acids (SCFAs), peptides, bacteriocins, proteins, and amino acids, all of which can confer health benefits to the host. Unlike probiotics, postbiotics are more stable during feed processing and under various environmental conditions. This enhanced stability, along with their enriched nutrient profile, makes postbiotics a promising alternative to probiotics in animal feed applications.
The use of postbiotics as a tool for improving the health of livestock and poultry shows great promise, owing to their numerous benefits and several advantages over probiotics and prebiotics. As metabolic byproducts or components derived from probiotic bacteria, postbiotics are less sensitive to environmental factors such as temperature, pH, and processing methods (Hossain et al., 2021). This enhanced stability allows them to retain their functional and beneficial properties over time, making them well-suited for diverse applications in animal health and nutrition (Thorakkattu et al., 2022).
Furthermore, we provided the information of postbiotics that can offer more advantages than live probiotics; for instance, (Rafique et al., 2023),
(a) Live probiotics may struggle to adhere to the gut mucosa due to the presence of a mucous layer that limits direct contact between bacteria and the epithelial surface. In contrast, postbiotics can more easily penetrate this mucous layer.
(b) Postbiotics pose no risk of infection from bacterial translocation from the intestinal lumen into the bloodstream, which is particularly important for immunocompromised or susceptible individuals. Additionally, they do not carry the risk of acquiring or transferring antibiotic resistance genes.
(c) Postbiotics offer practical advantages—they are easier to dose, transport, standardize, and store. Moreover, they have significant potential to support intestinal barrier function and may serve as an effective alternative to probiotics (Liu et al., 2023).
The benefits of postbiotics for gut health.
Postbiotics can inhibit the growth of pathogens and strengthen gut barrier function through the action of short-chain fatty acids (SCFAs). For instance, butyrate serves as an energy source for colon epithelial cells and the intestinal mucosa, thereby supporting gut integrity and reducing intestinal permeability. In addition to enhancing gut barrier function, butyrate plays a role in immunomodulation and exhibits anti-inflammatory effects while helping to improve growth performance, as illustrated in Figure 1.
Figure 1: Functions of postbiotics
Butyric acid has demonstrated in vitro antimicrobial activity against both Gram-positive bacteria (e.g., Enterococcus faecalis, Clostridium perfringens, Streptococcus pneumoniae, Streptococcus suis) and Gram-negative bacteria (e.g., Escherichia coli, Salmonella enterica Typhimurium, Campylobacter jejuni) (Kovenda et al., 2019).
The mode of action of sodium butyrate involves its conversion to butyric acid, which can penetrate bacterial cell walls primarily through diffusion. Once inside the cell, butyrate induces cytoplasmic toxicity by lowering the intracellular pH. This acidification disrupts key metabolic processes, depletes energy reserves, and leads to the excretion of protons (H⁺), which further diffuse into the bacterial cell and contribute to toxicity. The increased proton concentration interferes with ATP synthesis by impairing the bacterial cell’s ability to maintain proton gradients essential for energy production and metabolism. Ultimately, the drop in pH and metabolic disruption result in bacterial cell death (Ahsan et al.,2016).
Maximize the effectiveness of postbiotics in target animals.
Based on researches, postbiotic can be able to target gut-brain axis influence on serotonin to improve growth performance (Sofie et al., 2021; Ishii et al.,2019), gut health and nutrient digestion (Ahmed et al., 2014; Kumar et al., 2014), antimicrobial (Mantziari et al., 2020; Fong et al., 2020), anti-inflammation and Immune-microflora balance (Torino et al., 2015; Miyazawa et al., 2015; Maghsood et al., 2018;) including postbiotic/probiotic as an alternative ATB/ZnO (Ali et al., 2023).
FermNutral derived from the biological fermentation of the probiotic strain Clostridium butyricum, the main components of the product include amino acids, minerals, and beneficial metabolites classified as postbiotics. Rafique et al. (2023), writing in the Journal of Agriculture & Food Research, reviewed the principal classes of postbiotics with health-promoting effects:
- Short-chain fatty acids (SCFAs) –
Butyrate supports gut integrity, reduces intestinal permeability, modulates immunity, exerts anti-inflammatory actions, and suppresses pathogens. In broilers, butyrate also raises apparent total‑tract crude‑fat digestibility and apparent metabolizable energy (AME), enhancing overall digestion and nutrient absorption. - Antimicrobial peptides (bacteriocins) –
These peptides display activity against common pathogens, including Salmonella spp., Staphylococcus aureus, Yersinia enterocolitica, and Escherichia coli. - Quorum‑sensing (QS) interference –
Certain postbiotics inhibit pathogen biofilm formation by disrupting QS signaling, thereby curbing colonization and persistence. - Polysaccharides (e.g., teichoic acids) –
Contribute anti‑inflammatory and antimicrobial effects, further supporting host health. - B‑complex vitamins, proteins, and amino acids –
Provide additional nutritional and functional benefits that complement the antimicrobial and immunomodulatory actions of other postbiotic fractions.
Postbiotic product in poultry trials
FermNutral (FN) is a postbiotic product consisting of non-living microorganisms (inactivated bacteria) or their components that provide health benefits to the host. It also includes byproducts of probiotic activity in the gut, such as fermentation metabolites.
The main ingredient is calcium butyrate, which makes up 50% of the product. Other components include short-chain fatty acids (butyric acid, acetic acid, propionic acid), 18 amino acids, vitamins (B1, B2, B5, B6, B12, folic acid, E, and K), and minerals (Ca, Fe, Zn, Na, Mg, P, Mn, Cr).
Based on our trial data and correlated research publications, we can confidently say that FN improves productive performance and reduces feed costs, which contributes to higher profits and effective solutions in animal production. Typically, we focus on both performance and economic returns in animal production, especially for pigs, poultry, and aquatic species. Through extensive research conducted by CP BIO, we have found that using FN in aquatic animals such as Tilapia, Ruby fish, Penaeus vannamei, and Micropterus salmoides significantly enhances growth performance, feed efficiency, survival rates, and overall economic returns, as shown in Table 1.
Table 1: List of FermNutral Trials in CP BIO
| Animal species | Results / Conclusion | Site |
| Layers (HY-Line; 256 birds: 50 wks) +FN 0.3 kg/ton of feed, 6 weeks * (p<0.05) | *EW+3%; FCR -0.03 (2.11-2.08) Dirty egg rate -0.28% (0.45-0.17) *Yolk Index +8% (0.38-0.41) | Henan Agriculture U., China (2021) |
| Broilers Effect FN on Ig (g/L) & Perf.+FN 0.5 kg/ton of feed | IgA +13%, IgG +10%, IgM +24% ADG+15%, FCR -0.05 (2.14-2.09) | Guizhou U., China (2020) |
| Broilers (Ross 308; 44,000 birds) +FN 0.5 kg/ton of feed | ADG+6% FCR -0.04 (1.63-1.59), SR +2% EPI +44 (421-377) | Kaifeng, Henan, China (2020) |
| Broilers (AA; 97,500 birds) +FN 0.3 kg/ton feed) * (p<0.05) | FCR -0.04 (1.77-1.73), SR +2% EPI +23 (338-315) vs CCB +10 *V/C Duo-Je.+(29-42)% vs CCB +(18-33)% | Broiler farm in Lvliang city, Shanxi Province, China (2022) |
| Broilers (AA male; 300 birds) + FN 0.5 kg/ton of feed *(p<0.05) | ADG+4.2%, *FCR -0.11 (1.43-1.32), *EPI+57 ( 430-487) | Commercial broiler farm, Thailand (2024) |
| Ruby fish (90,000) +FN 2-3 kg/ton feed, 55 days | BWG+11%, FCR -12%, SR +6.5% | Had Yai Province, Thailand (2024) |
| Nile tilapia +FN 3-5 kg/ton feed, 23 days *(p<0.05) | BWG+23.4%, FCR -13.4%, SR +14.8% Amylase +54%, Lipase +105% | Supranee et al., 2024 Thai J Vet Med 2024 54 (Suppl.2): 185-186 |
Conclusions
FermNutral (FN) is a biological fermentation product derived from the probiotic strain Clostridium butyricum. It primarily contains short-chain fatty acids (SCFAs), especially butyrate, along with amino acids, minerals, and beneficial metabolites acting as postbiotics. Essentially, FN functions through the diet-gut-microbe axis to provide effective animal health solutions. Butyrate mainly supplies energy to the epithelial cells of the colon, improving digestion and nutrient absorption while controlling pathogens, maintaining immune balance, and reducing inflammation. Therefore, the multi-modal actions of FN help support gut function, enhancing animal performance and profitability.
References available on request
By Dr. Natthanan Nukitrangsan, Ph.D
Feed Nutritionist & Technical Consultant, CP BIO