副乾酪乳桿菌
副乾酪乳桿菌（學名：），常以其縮寫稱呼為LP菌，是一種革蘭氏陽性菌，乳桿菌屬中的一菌種。 為常見的益生菌。副乾酪乳桿菌以偏利共生形式運作。常見於與人類相關的棲息地，包括人體內的腸道、口腔，以至人體外的糞渠、青貯飼料及前述的奶製品。正如「乳桿菌」這名字所指，本菌種有著與芽孢桿菌屬相似的桿狀形態，寬約2.0到4.0μm，長約0.8到1.0μm。
1989年，透過的結果，科學家將NCDO 151（=ATCC 25302）菌株從乾酪乳桿菌分離出來。 現時，科學家從不同的環境中分離出34種不同的菌株，當中有16種是從奶製品分離出來，10種從植物分離出來，8種從人類或其他動物的消化道分離出來。本物種無論是從基因型或從表型都難以從其他諸如乾酪乳桿菌或（""）等其他物種分辨過來。然而，科學家還是可以透過這些菌的發酵譜來將之分辨開來。本菌種專門用於生物食品處理程序，以及用於製作營養補充劑，特別是幫助有消化道不適的病患。
儘管益生菌被認為是安全的，但它們可能引起細菌與宿主的相互作用以及對健康的不利影響。在某些情況下，使用益生菌可能會導致菌血症。現時尚未確定益生菌療法的益生菌菌株、使用頻率、劑量和持續時間之間的關係。
副乾酪乳桿菌在生理学屬於革蘭氏陽性菌，兼性異發酵，非芽孢形成的微生物。副乾酪乳桿菌的細胞通常為桿棒狀，大小範圍為寬度2.0μm至4.0μm，長度0.8至1.0μm。這種生物體是不運動的。副乾酪乳桿菌細胞通常具有方形末端，並且可以單一形式或鏈狀存在。
副乾酪乳桿菌的最佳生長溫度範圍是 在10至37°C。當溫度超過40°C，乳桿菌就不會再生長。然而，即使在最高溫度72°C下，乳桿菌仍然可存活約40秒。由於副乾酪乳桿菌是異發酵的：大多數菌株會產生乳酸。
副乾酪乳桿菌無論是在人類胃腸道或一般的植物，均為其常見的棲所。天然發酵的蔬菜、牛奶和肉也類可能含有副乾酪乳桿菌。
副乾酪乳桿菌屬於細菌界厚壁菌門芽孢桿菌綱乳桿菌目的。關於副乾酪乳桿菌與乾酪乳桿菌的爭論一直都是激烈的辯論議題。 Most of the species profiled as "L. casei" or "L. paracasei" have been found to be part of the same species. In 1989, it was proposed that "L. paracasei" be designated a subspecies (paracasei) to account for the species that it shares DNA 同源 with. It has been shown their names have been used interchangeably in scientific literature. 16S 核糖体RNA sequence 同源 has confirmed the relatedness between these species.
Historically, the difference between "Lactobacillus paracasei" and other "lactobacilli" has been based on 生物化学 characteristics. There is an approximately 90% sequence identity between "卡塞伊杰罗拉", "paracasei", and "rhamnosus". However, there are some differential criteria that are commonly used to differentiate between them. These differential criteria include nutritional requirements and growth environment. "L. paracasei" has been found to show specific differences with other "Lactobacillus" spp. in that it is somewhat heat resistant, grows well in ripening cheese, and it has high 蛋白酶解 activity.
"L. paracasei" has been found to have 34 strains. These strains have been isolated from various countries around the world. Although there is a small correlation between 系统发生学 relatedness and origin of isolation, currently there is not enough evidence to support direct proof of the relationship.
"L. paracasei's" genome contains circular 脱氧核糖核酸 and varies slightly among the different strains isolated. On average, the 基因組 are 2.9 to 3.0 million base pairs (commonly abbreviated Mb). It has a GC含量 between 46.2 and 46.6% and is predicted to encode about 2800 to 3100 proteins. The difference in the genomes of these strains lies in variant s, s, and 多糖. Many of the commonly coded proteins are cell-surface associated cell-wall 水解酶s that protect the cell against 细胞凋亡. These enzymes have been shown to provide cellular protection to human 上皮組織 cells.
Genetic diversity for the different "L. paracasei" genomes was assessed using 多位点序列分型 (MLST) and (AFLP). MLST is a technique used for classifying microbes by the use of DNA fragments from essential genes of the organism. AFLP is a 聚合酶链式反应 (PCR) tool used in 遺傳指紋分析 to amplify a desired 脱氧核糖核酸 fragment with the use of 限制酶 and 配體.
副乾酪乳桿菌已被鑑定為具有益生菌性質的細菌。
副乾酪乳桿菌是正常人類腸道的一部分。乾酪乳桿菌的IMPC2.1菌株可以是化學預防醫學在消化道的細胞。胃腸道細胞的凋亡和生長易受已熱滅活和有活力的IMPC2.1菌株的影響。 副乾酪乳桿菌8700：2菌株已從健康的人的胃腸道黏膜和糞便中分離出來。8700:2菌株亦被發現可抑制腸道沙門氏菌及幽門螺桿菌這兩種在胃腸道中常見的病原體。8700:2菌株可分解果寡糖和菊粉，而菌株同時可在兩者上快速生長並產生乳酸作為最終產物。副乾酪乳桿菌已被證明可抑制大腸桿菌的细菌活性，而大腸桿菌是引致腹瀉的常見菌種，因此副乾酪乳桿菌被應用於治療腹瀉。包含副乾酪乳桿菌的活菌製劑可與常規療法結合使用，以治療溃疡性结肠炎。一項系統綜述為副乾酪乳桿菌LP-33菌株治療變應性鼻炎提供了有益的臨床和免疫學作用的重要證據。
副乾酪乳桿菌的D3-5菌株經過「熱殺」（）後，其細胞壁會析出，可改善實驗鼠與衰老相關的腸道滲出、炎症，並改善其身體和認知功能。
除了各種和消化道相關的病變，2011年，副乾酪乳桿菌首次用於預防龋齿。這是因為副乾酪乳桿菌能夠識別，使其附著並導致結塊，而變形鏈球菌因此無法再附著在牙齒上，而會被唾液沖洗掉或在刷牙時被除去。
The manipulation of the gut microbiota is complex and may cause bacteria-host interactions. Although probiotics are considered safe, when they are used by oral administration there is a risk of passage of viable bacteria from the gastrointestinal tract to the internal organs (bacterial translocation) and subsequent bacteremia, which can cause adverse health consequences. Some people, such as those with immune compromise, short bowel syndrome, central venous catheters, cardiac valve disease and premature infants, may be at higher risk for adverse events.
Currently, the probiotic strain, frequency, dose and duration of the probiotic therapy are not established. Live bacteria might not be essential because of beneficial effects of probiotics seems to be mediated by their DNA and by secreted soluble factors, and their therapeutic effects may be obtained by systemic administration rather than oral administration.
乳酸菌（；一般縮寫作）是在1900年代初進行分類和分組的。牠們受到注意，主要是由於科學家觀察到這些細菌在不同食品（尤其是乳製品）中的相互作用。1991年，荷蘭微生物學家马丁努斯·威廉·拜耶林克從之前已知的LAB組中分離出了革蘭氏陽性細菌，就是乳酸桿菌。 副乾酪乳桿菌最近已被歸類為乾酪乳桿菌益生菌群組的成員。但是，在生物分类学上，其具體位置並不明確。1996年，Dicks, Duplessis, Dellaglio & Lauer提出副乾酪乳桿菌 並不是一個獨立的物種。