|This article is about a/an element in Choudenshi Bioman.|
Anti-Bio Particles (反バイオ粒子 Han Baio Ryūshi) are special particles devised by the Anti-Bio Union during their civil war with those who had invented and were supported by Bio Particles on the planet Bio 500 years in the past. Fearful of the weaponization of Bio Particles, the effects of which were unknown to the people of the planet at the time, these antithesis particles were devised and used by the opposing faction in the Bio War. Their most notable and infamous usage were for the development of a special warrior machine used by the Anti-Bio Union to crush their opponents: the assassin known as Bio Hunter Silva. The clash of Bio Particles and Anti-Bio Particles were enough to weaken the planet, with the Anti-Bio Particles in particular weakening to the planet; despite both sides becoming depleted, the Anti-Bio Particles overusage was to the point that it ultimately damaged the planet itself, leading to its final destruction. While the civil war ultimately lead to the destruction of planet Bio, remnants of Anti-Bio Particles remained throughout the universe, both throughout space after the planet's destruction as well as those within Silva and his mecha, Balzion.
After Bioman emerged on Earth to fight against the Neo Empire Gear, Doctor Man collected whatever remaining Anti-Bio Particles he could through space to use for his Bio Killer Gun, knowing that the particles would be enough to weaken the Bio Particles and, thus, Bioman. Giving the gun to Mason, the android uses the gun against Bioman, only to have Mika Koizumi, the original Yellow4, take every shot she can in order to protect her teammates from the attack. The effects of the Anti-Bio Particles weakened Mika to the point that the Beastnoid Psygorn's Garden of Bombs attack was enough to kill her, even with the protection of her Bio Suit, due to the disabling of the power within her. However, Mika's sacrifice likewise wasted all of the Anti-Bio Particles within the Bio Killer Gun, making it unavaiable for any further use by Doctor Man and Gear.
Ultimately, Bio Hunter Silva, the android of the Anti-Bio Union, came to Earth with his own Anti-Bio Particles, primarily within his Bi Buster Gun which was more powerful than the Bio Killer Gun used by Gear. However while the shots were more effective, the Anti-Bio Particles were not as lethal to Bioman due to improved Bio Suits and fully awakened Bio Particles gained through the team's training since the incident that killed Mika. Regardless, Silva remained a lethal threat to the team with his power and ability to target and attack Bioman with Anti-Bio weaponry.
During the climactic battles between Bioman, Gear and Silva, the power of Anti-Bio Particles remained a threat and a valuable asset to all those within the conflict. It was key towards the revelation of the mecha Balzion, due to a swarm of the particles emerging around a lab where Professor Shibata set up a lab after the destruction of his initial lab by Silva; however this likewise became a hint at its true destructive nature due to the massive earthquakes that occurred from the emission. As Balzion was used by Gear and Silva during the final showdown, Bioman is forced to overcome them with a combination of their power, their Bio Robo mecha, and Peebo to defeat the Bio Hunter's ultimate weapon.
Ultimately, Doctor Man acquires and weaponizes more Anti-Bio Particles from his Balzion research for two final ultimate weapons for his arsenal. The first, King Megas, was a Balzion-equivalent mecha built by the Gear scientist using his science and Anti-Bio technology to confront Bioman one final time in hopes of finishing them off. After King Megas is defeated, he reveals his final failsafe: the Anti-Bio Bomb, a weapon of concentrated Anti-Bio Particles with enough power to annihilate Earth when it explodes similar to Bio's end. However, due to the influence of Bioman and his own son Shuichi, the bomb is disabled before it explodes, bringing an end to the threat of the legacy of the ancient Bio war.