Should I keep them natural?

SELECT * FROM gallery2 WHERE topic_id="437869" UNION SELECT * FROM gallery2 WHERE topic_id="510503" UNION SELECT * FROM gallery2 WHERE topic_id="342848" UNION SELECT * FROM gallery2 WHERE topic_id="1047166" UNION SELECT * FROM gallery2 WHERE topic_id="1612556" UNION SELECT * FROM gallery2 WHERE topic_id="90976" UNION SELECT * FROM gallery2 WHERE topic_id="172702" UNION SELECT * FROM gallery2 WHERE topic_id="1466065" UNION SELECT * FROM gallery2 WHERE topic_id="45821" UNION SELECT * FROM gallery2 WHERE topic_id="1464188" UNION SELECT * FROM gallery2 WHERE topic_id="590842" UNION SELECT * FROM gallery2 WHERE topic_id="210945" UNION SELECT * FROM gallery2 WHERE topic_id="1764979" UNION SELECT * FROM gallery2 WHERE topic_id="1055893" UNION SELECT * FROM gallery2 WHERE topic_id="1547754" UNION SELECT * FROM gallery2 WHERE topic_id="555171"