Sys Rev Pharm 2021;12(03):829-834 A multifaceted review journal in the field of pharmacy 829 Systematic Reviews in Pharmacy Vol 12, Issue 3, Mar-April 2021 Probiotic Lactobacillus sp. Improved Performance of Broiler Chicken: A Review Herinda Pertiwi, Mohamad Yusril Nur Mahendra Department of Health Studies, Faculty of Vocational Studies, Airlangga University Jalan Dharmawangsa Dalam 28-30, Surabaya – Indonesia ABSTRACT Probiotic Lactobacillus sp. is considered a potential resource for improving the performance of broiler chicken in Indonesia. Administration of Lactobacillus sp. Probiotics could increase the Average Daily Gain (ADG) and body weight of broiler chickens by increasing intestinal villi permeability, so that nutrient absorption could be optimal. Use of Lactobacillus sp. in the ration is often combined with other probiotics, prebiotics, phytoadditives, and organic acids to support the feed intake and feed conversion ratio. Lactobacillus sp. also able to produce various bioactive compounds such as the enzyme manase which could be in symbiosis with mannan-oligosaccharides (MOS) to increase the bodyweight of broiler chickens and bacteriocins that against pathogenic bacteria such as Salmonella typhimurium, Staphylococcus aureus and Bacillus cereus. Probiotic metabolic activity of Lactobacillus sp. could suppress the growth of pathogenic bacteria by creating an acid digestive environment. In addition, immunity and hematological conditions such as erythrocytes, hematocrit, leukocytes, MCV, MCH, and MCHC were maintained well by Lactobacillus sp. supplementation in the ration. This review aims to highlight the potential of probiotic Lactobacillus sp to modulate broiler microbiome and metabolic status to enhance performance and health. Keywords: Broiler chicken, Lactobacillus sp., Production performance, Probiotics Correspondence: Herinda Pertiwi Department of Health Studies Faculty of Vocational Studies Airlangga University. Jalan Dharmawangsa Dalam 28-30, Surabaya – Indonesia Email: herinda.pertiwi@vokasi.unair.ac.id INTRODUCTION Antibiotics have been used as ingredients in animal feed mixtures in Indonesia since 1946 with the aim of improving digestibility, growth, and health of livestock. However, its use as a growth driver has the potential to stimulate resistance (Krisnan et al., 2019). Therefore, the Indonesian government has issued a regulation concerning the prohibition of the administration of antibiotic growth promoters in Law no. 18/2009 jucto No.41 / 2014 concerning Animal Husbandry and Animal Health which states the prohibition of the administration of feed mixed with certain hormones and/or feed additive antibiotics with the classification of veterinary drugs listed in the Minister of Agriculture Regulation No.14 / Permentan / PK .350/5/2017. The prohibition of antibiotics in feed is also strengthened by the issuance of MOA No. 22/2017 concerning Registration and Distribution of Feed, which requires a statement not to use antibiotic growth promoters in feed formulas produced by producers. In the previous study by Cardinal et al., (2019) found that withdrawing antibiotic growth promoters from the broiler diet increased production costs, which in turn increased the price of poultry meat. Even though the consumption of chicken meat in Indonesia is about 6.1 kg per capita on average, this value is still lower than in other countries. Therefore, efforts are needed to replace the role of antibiotics growth promoters with an affordable, safe, and natural additive in the feed. Currently, alternatives used for antibiotics include probiotics, prebiotics, competitive exclusion, enzymes, and organic acids. The administration of probiotics is expected to be a candidate for AGP substitution. Probiotics are non-pathogenic living organisms present in some foods which have positive effects on the health of the hosts if they enter the body in sufficient amounts (Mousavi et al., 2018). The most selected probiotics are gram-positive bacteria belonging to Bacillus, Enterococcus, Lactobacillus, Pediococcus, and Streptococcus. It is not only bacteria that are used as probiotics; yeast and fungi have been used, such as Saccharomyces cerevisiae and Kluyveromyces (Selaledi et al., 2020). The presence of Lactobacillus sp., a common microbiota in the chicken broiler gastrointestinal tract, is essential to maintaining the ecological balance in the microbiota. The supplementation of probiotics to feed could maintain the balance of microflora in the digestive tract and inhibit pathogenic bacteria, increase digestive enzyme activity, reduce ammonia production, increase feed intake and digestion, neutralize enterotoxins and stimulate the immune system. Isolate Lactobacillus sp. could be taken from native Indonesian chicken which has great potential (Yulianto and Lokapirnasari, 2018). Probiotic Classification Probiotics are classified by observing the similarities of qualities, such as physical characteristics, metabolic needs, and metabolic end products. These similarities grouped into one genus, while the special characteristics that exist in one individual and do not exist in another individual will become the name of the species. The general classification of probiotics could be seen in table 1. Table 1. The general classification of probiotics Genus Species e.g., Strain Ref. Lactobacillus murinus Ar3 Harimurti et al., 2010 CR147 Harimurti et al., 2010 plantarum BS22 Zeng et al., 2018 B1 Peng et al., 2016 acidophilus D2 Cesare et al., 2020 A3B3 Sa’diyah et al., 2020