婴儿初乳富含营养和免疫成分，如抗体和抗菌蛋白；在成人领域，牛初乳补充剂的年销售额在一年内飙升155%，以液体、粉末和胶囊形式销售。爱好者声称它可减轻炎症、改善消化和免疫功能、增强肌肉和有氧能力并美容皮肤，但这些主张多超前于证据。

关于免疫作用，波兰对28名游泳和铁人三项运动员的试验中，每天补充25克牛初乳持续12周，仅带来轻微但“有利”的唾液IgA升高；一项涵盖5个随机对照试验、共152名运动者的综述显示，上呼吸道感染发作次数减少38%。然而，这些研究样本小且集中在免疫受压的高强度运动人群，其他研究即使使用大剂量也未见免疫指标有一致改善。

在肠道健康方面，一项乌干达试验纳入84名与HIV相关慢性腹泻的成人，添加初乳补充的治疗组不仅腹泻更快缓解，9周后体重平均增加11%，而对照组体重未恢复；这被归因于初乳中的抗体及乳铁蛋白、乳过氧化物酶等抗菌蛋白减少“肠漏”。初乳可能通过降低炎症和改善铁携带来提高有氧能力，但现有研究未证实其增加肌肉量或美容皮肤的效果，而每天仅约3克的剂量，每月成本就可超过60美元。

I’m checking how to separate paragraphs in plain text. It seems that using blank lines is the way to go, just as the system requires. I shouldn't include any numbering, bullets, or extra text before or after the six paragraphs. So, I've got it: blank lines only between the paragraphs, with none at the beginning or end. Sounds good! I’m ready to write following these guidelines.

Colostrum, the nutrient- and antibody-rich “first milk,” has moved from infant nutrition into adult supplements, driving a 155% year-on-year increase in sales of bovine colostrum products sold as liquids, powders, and capsules. Enthusiasts credit it with reducing inflammation, aiding digestion and immunity, enhancing muscle and aerobic performance, and rejuvenating skin, but the evidence base is far more limited than the marketing.

In immune-focused trials, 28 Polish swimmers and triathletes taking 25 grams of bovine colostrum daily for 12 weeks showed only modest but “favourable” increases in salivary immunoglobulin A. A review of five randomized controlled trials with 152 exercising participants reported a 38% reduction in upper-respiratory-illness episodes and faster recovery, yet these small studies involved athletes with exercise-weakened immunity, and other research has found little or no immune benefit even at high doses.